全文获取类型
收费全文 | 354篇 |
免费 | 21篇 |
专业分类
林业 | 13篇 |
农学 | 10篇 |
26篇 | |
综合类 | 16篇 |
农作物 | 8篇 |
水产渔业 | 44篇 |
畜牧兽医 | 192篇 |
园艺 | 3篇 |
植物保护 | 63篇 |
出版年
2023年 | 2篇 |
2022年 | 14篇 |
2021年 | 20篇 |
2020年 | 14篇 |
2019年 | 9篇 |
2018年 | 13篇 |
2017年 | 10篇 |
2016年 | 18篇 |
2015年 | 24篇 |
2014年 | 20篇 |
2013年 | 34篇 |
2012年 | 30篇 |
2011年 | 21篇 |
2010年 | 15篇 |
2009年 | 11篇 |
2008年 | 19篇 |
2007年 | 16篇 |
2006年 | 16篇 |
2005年 | 18篇 |
2004年 | 14篇 |
2003年 | 15篇 |
2002年 | 10篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有375条查询结果,搜索用时 15 毫秒
101.
102.
103.
Effect of Leukemia Inhibitory Factor and Forskolin on Establishment of Rat
Embryonic Stem Cell Lines
Masumi HIRABAYASHI Teppei GOTO Chihiro TAMURA Makoto SANBO Hiromasa HARA Shinichi HOCHI 《The Journal of reproduction and development》2014,60(1):78-82
This study was designed to investigate whether supplementation of 2i medium with
leukemia inhibitory factor (LIF) and/or forskolin would support establishment of
germline-competent rat embryonic stem (ES) cell lines. Due to the higher likelihood of
outgrowth rates, supplementation of forskolin with or without LIF contributed to the
higher establishment efficiency of ES cell lines in the WDB strain. Germline transmission
competency of the chimeric rats was not influenced by the profile of ES cell lines until
their establishment. When the LIF/forskolin-supplemented 2i medium was used, the rat
strain used as the blastocyst donor, such as the WI strain, was a possible factor
negatively influencing the establishment efficiency of ES cell lines. Once ES cell lines
were established, all lines were found to be germline-competent by a progeny test in
chimeric rats. In conclusion, both LIF and forskolin are not essential but can play a
beneficial role in the establishment of “genuine” rat ES cell lines. 相似文献
104.
105.
106.
Tomoyuki Shimazu Liushiqi Borjigin Yuki Katayama Meihua Li Takumi Satoh Kouichi Watanabe Haruki Kitazawa Sang‐gun Roh Hisashi Aso Katoh Kazuo Yoshihito Suda Akiko Sakuma Mituru Nakajo Keiichi Suzuki 《Animal Science Journal》2014,85(4):365-373
We recently developed a Landrace line that is resistant to mycoplasmal pneumonia of swine (MPS) infection by genetic selection for five generations, and we reported that the immunophenotype of this line is different from that of the non‐selected line in terms of changes in peripheral blood leukocyte population after MPS vaccination. This study followed up previous findings demonstrating changes in soluble factors in blood, namely, hormones, Mycoplasma hyopneumoniae‐specific immunoglobulin G (IgG), and cytokines. These two lines were injected with MPS vaccine on days ?7 and 0 after blood sampling on those days, and blood samples were collected on days ?14, ?7, 0, 2, 7 and 14. We found changes in the levels of many hormones and cytokines in both lines. However, we found that only growth hormone (GH) and interferon (IFN)‐γ levels were statistically different between these two lines. GH concentration was reduced (day 0) and IFN‐γ concentration was increased (day 14) in the MPS‐selected line compared with the non‐selected line, despite unchanged IFN‐γ messenger RNA expression in blood cells. Although detailed mechanisms underlying these phenotypes remain unsolved, these traits would be useful to improve MPS resistance in pig production and provide an insight into MPS infection. 相似文献
107.
Ishii N Nakahigashi K Baba T Robert M Soga T Kanai A Hirasawa T Naba M Hirai K Hoque A Ho PY Kakazu Y Sugawara K Igarashi S Harada S Masuda T Sugiyama N Togashi T Hasegawa M Takai Y Yugi K Arakawa K Iwata N Toya Y Nakayama Y Nishioka T Shimizu K Mori H Tomita M 《Science (New York, N.Y.)》2007,316(5824):593-597
Analysis of cellular components at multiple levels of biological information can provide valuable functional insights. We performed multiple high-throughput measurements to study the response of Escherichia coli cells to genetic and environmental perturbations. Analysis of metabolic enzyme gene disruptants revealed unexpectedly small changes in messenger RNA and proteins for most disruptants. Overall, metabolite levels were also stable, reflecting the rerouting of fluxes in the metabolic network. In contrast, E. coli actively regulated enzyme levels to maintain a stable metabolic state in response to changes in growth rate. E. coli thus seems to use complementary strategies that result in a metabolic network robust against perturbations. 相似文献
108.
Ström L Karlsson C Lindroos HB Wedahl S Katou Y Shirahige K Sjögren C 《Science (New York, N.Y.)》2007,317(5835):242-245
Sister-chromatid cohesion, established during replication by the protein complex cohesin, is essential for both chromosome segregation and double-strand break (DSB) repair. Normally, cohesion formation is strictly limited to the S phase of the cell cycle, but DSBs can trigger cohesion also after DNA replication has been completed. The function of this damage-induced cohesion remains unknown. In this investigation, we show that damage-induced cohesion is essential for repair in postreplicative cells in yeast. Furthermore, it is established genome-wide after induction of a single DSB, and it is controlled by the DNA damage response and cohesin-regulating factors. We thus define a cohesion establishment pathway that is independent of DNA duplication and acts together with cohesion formed during replication in sister chromatid-based DSB repair. 相似文献
109.
Ishii K Ogiyama Y Chikashige Y Soejima S Masuda F Kakuma T Hiraoka Y Takahashi K 《Science (New York, N.Y.)》2008,321(5892):1088-1091
The centromere is essential for the inheritance of genetic information on eukaryotic chromosomes. Epigenetic regulation of centromere identity has been implicated in genome stability, karyotype evolution, and speciation. However, little is known regarding the manner in which centromere dysfunction affects the chromosomal architectures. Here we show that in the fission yeast Schizosaccharomyces pombe, the conditional deletion of the centromere produces survivors that carry either a neocentromere-acquired chromosome at the subtelomeric region or an acentric chromosome rescued by intertelomere fusion with either of the remaining chromosomes. The ratio of neocentromere formation to telomere fusion is considerably decreased by the inactivation of genes involved in RNA interference-dependent heterochromatin formation. By affecting the modes of chromosomal reorganization, the genomic distribution of heterochromatin may influence the fate of karyotype evolution. 相似文献
110.
Mitochondrial and nuclear genomic diversities of 8 carrot (Daucus carota ssp. sativus) varieties, including 6 pure lines and
2 cytoplasmic male sterile (cms) lines, were taxonomically identified using PCR with 19 RAPD primers. Dendrograms based on
polymorphisms of both mitochondrial and nuclear genomes were constructed. According to the dendrogram of the mitochondrial
genome revealed by RAPD, 4 differentiated clusters formed, in good accordance with the classification based on analyses with
restriction enzyme digestion. Two cms lines were grouped into the same cluster, as genetically separated from the others.
Thus, the cytoplasm donors of these male sterile lines were thought to be wild carrots. Conversely, RAPD analysis of the nuclear
genome for these eight cultivars revealed no evident clusters although some cultivars were of a similar origin or place of
cultivation. A correlation between nuclear and mitochondrial dendrograms was absent. RAPD has proved to be a useful tool for
identifying mitochondrial and nuclear genomes. This technique will greatly aid in promoting efficient improvement of carrots.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献