全文获取类型
收费全文 | 208篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
林业 | 3篇 |
农学 | 11篇 |
46篇 | |
综合类 | 11篇 |
农作物 | 6篇 |
水产渔业 | 11篇 |
畜牧兽医 | 117篇 |
园艺 | 2篇 |
植物保护 | 3篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 6篇 |
2020年 | 8篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 8篇 |
2014年 | 8篇 |
2013年 | 22篇 |
2012年 | 12篇 |
2011年 | 16篇 |
2010年 | 8篇 |
2009年 | 15篇 |
2008年 | 15篇 |
2007年 | 17篇 |
2006年 | 19篇 |
2005年 | 14篇 |
2004年 | 10篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1989年 | 2篇 |
1982年 | 1篇 |
排序方式: 共有210条查询结果,搜索用时 31 毫秒
91.
Dehal P Satou Y Campbell RK Chapman J Degnan B De Tomaso A Davidson B Di Gregorio A Gelpke M Goodstein DM Harafuji N Hastings KE Ho I Hotta K Huang W Kawashima T Lemaire P Martinez D Meinertzhagen IA Necula S Nonaka M Putnam N Rash S Saiga H Satake M Terry A Yamada L Wang HG Awazu S Azumi K Boore J Branno M Chin-Bow S DeSantis R Doyle S Francino P Keys DN Haga S Hayashi H Hino K Imai KS Inaba K Kano S Kobayashi K Kobayashi M Lee BI Makabe KW Manohar C Matassi G Medina M Mochizuki Y Mount S 《Science (New York, N.Y.)》2002,298(5601):2157-2167
The first chordates appear in the fossil record at the time of the Cambrian explosion, nearly 550 million years ago. The modern ascidian tadpole represents a plausible approximation to these ancestral chordates. To illuminate the origins of chordate and vertebrates, we generated a draft of the protein-coding portion of the genome of the most studied ascidian, Ciona intestinalis. The Ciona genome contains approximately 16,000 protein-coding genes, similar to the number in other invertebrates, but only half that found in vertebrates. Vertebrate gene families are typically found in simplified form in Ciona, suggesting that ascidians contain the basic ancestral complement of genes involved in cell signaling and development. The ascidian genome has also acquired a number of lineage-specific innovations, including a group of genes engaged in cellulose metabolism that are related to those in bacteria and fungi. 相似文献
92.
Chen T Hiroko T Chaudhuri A Inose F Lord M Tanaka S Chant J Fujita A 《Science (New York, N.Y.)》2000,290(5498):1975-1978
Diploid yeast cells repeatedly polarize and bud from their poles, probably because of highly stable marks of unknown composition. Here, Rax2, a membrane protein, was shown to behave as such a mark. The Rax2 protein itself was inherited immutably at the cell cortex for multiple generations, and Rax2 was shown to have a half-life exceeding several generations. The persistent inheritance of cortical protein markers would provide a means to couple a cell's history to the future development of a precise morphogenetic form. 相似文献
93.
94.
Gentoku Nakase Yoshizumi Nakagawa Shigeru Miyashita Toshiro Nasu Shigeharu Senoo Hiroko Matsubara Mitsuru Eguchi 《Fisheries Science》2007,73(4):784-791
Bacterial community structures were analyzed in water used for rearing fish larvae by fluorescence in situ hybridization. In Experiment 1, red sea bream Pagrus major larvae were reared in two commercial seed production tanks. The survival rate in Tank 1 was higher than in Tank 2, even though
phytoplankton, Nannochloropsis sp., was added to both tanks. In Tank 2, γ-proteobacteria became dominant (∼70% of total bacteria) on day 13, there after
heavy larval mortalities occurred. In Tank 1, however, α-proteobacteria and the Cytophaga-Flavobacterium cluster were predominant from day − 1 until day 13; no significant mortality was recorded. In Experiment 2, marble goby Oxyeleotris marmoratus larvae were cultured with or without Nannochloropsis sp. At the end of the experiment, larval survival rates in aquaria with Nannochloropsis sp. were significantly (P <0.05) higher than those without. In rearing water without Nannochloropsis sp., γ-proteobacteria increased during rearing. In rearing water with Nannochloropsis sp., α-prote obacteria and the Cytophaga-Flavobacterium cluster were predominant at the beginning of the experiments and the relative abundance of γ-proteobacteria was maintained
at a lower level throughout the experiments. The predominance of α-proteobacteria and the Cytophaga-Flavobacterium cluster appears to be a good indicator of successful larval production. 相似文献
95.
The toadfish,Opsanus tau, lacks renal glomeruli and macula densa, but has high renal renin activity and abundant granulated cells in renal arteries
and arterioles. Reduction of blood pressure (BP) or blood volume by hemorrhage or vasodilatory drugs causes renin release,
indicating that an intrarenal or extrarenal pressure- or volume-sensitive mechanism exists for controlling renin release in
the toadfish. Thus, we examined whether 1) β-adrenergic receptor-mediated activation of renin release, and 2) calcium influx
which may underlie the baroreceptor mechanism are involved in the cellular control of renin release. Acute injection of isoproterenol
(1 μg/kg, n = 6) decreased BP and increased plasma renin activity (PRA) 4–5 fold in unanesthetized toadfish. Propranolol abolished
both effects, but did not decrease basal PRA levels.In vitro superfusion of renal slices with bicarbonate Ringer's solution showed a steady secretion of renin, and addition of 50 mM
K+ (K+ methylsulfate replacing NaCl, n = 10) to the superfusate markedly suppressed renin secretion. Nifedipine (10−5 M, n = 8) completely restored the high K+-induced inhibition of renin secretion from renal slices, whereas isoproterenol (10−4 M, n = 6) neither increased basal renin secretion nor restored K+-induced renin suppression. These results suggest that calcium influx may mediate inhibitory messages for renin secretion,
while the β-adrenoceptor-mediated activation of granulated cells appears absent in toadfish. 相似文献
96.
Yousuke NANIWA Keisuke NAKATSUKASA Shohei SETSUDA Shinya OISHI Nobutaka FUJII Fuko MATSUDA Yoshihisa UENOYAMA Hiroko TSUKAMURA Kei-ichiro MAEDA Satoshi OHKURA 《The Journal of reproduction and development》2013,59(6):588-594
Kisspeptin is a key molecule that stimulates gonadotropin secretion via release of
gonadotropin-releasing hormone (GnRH). In the present study, our aim was to
investigate whether kisspeptin has stimulatory effects on follicular development via
GnRH/gonadotropin secretion in cows. Japanese Black beef cows were intravenously
injected with full-length bovine kisspeptin [Kp-53 (0.2 or 2 nmol/kg)] or vehicle 5
days after they exhibited standing estrus (Day 0). In cows injected with Kp-53 at 2
nmol/kg, the follicular sizes of the first dominant follicles increased on Day 6 and
thereafter. Ovulation of the first dominant follicle occurred in 1 out of 4 cows
treated with Kp-53 at 2 nmol/kg. Injection of Kp-53 at 2 nmol/kg increased the
concentration of plasma luteinizing hormone (LH) but not follicle-stimulating
hormone, over a 4-h period following injection in all cows. The present study
suggests that administration of full-length kisspeptin causes LH secretion, which is
sustained for a few hours, and it is capable of stimulating follicular development
and/or ovulation. 相似文献
97.
Doi T Kotani Y Takahashi K Hashimoto S Yamada N Kokoshima H Tomonari Y Wako Y Tsuchitani M 《Journal of toxicologic pathology》2010,23(2):103-106
Spontaneous malignant mesothelioma was found in a 104-week-old male Crj:CD(SD) rat. The tumor was scattered on the surface of the lung, heart, mediastinal pleura and thoracic wall and metastasized to the alveolar septa. Histopathologically, small flattened or cuboidal tumor cells proliferated with stroma, formed almost normal papillary structures and reacted positively to colloidal iron stain and immunohistochemical staining for mesothelin. Round hyalinous stromata were pronounced, which is a characteristic feature, and the possible reason for this is as follows; at first, a small amount of collagen fibers was formed in the center of the clusters of several tumor cells, and then the cell clusters expanded like balloons with an increase in the collagen fibers. 相似文献
98.
Wakabayashi N Tsujino M Tajiri M Taki M Koshino A Ikeda H Fukushima N Tsujiuchi T 《Journal of toxicologic pathology》2010,23(1):63-66
Lysophosphatidic acid (LPA) is a bioactive phospholipid that stimulates cell proliferation and migration, and protects cells from apoptosis. It interacts with specific G protein-coupled transmembrane receptors. Recently, frequent mutations of the LPA receptor-1 (LPA1) gene were detected in rat lung adenocarcinomas induced by N-nitrosobis(2-hydroxypropyl)amine (BHP). In this study, to evaluate the involvement of other LPA receptor gene alterations during lung carcinogenesis, we investigated mutations of the LPA2, LPA3, LPA4 and LPA5 genes in lung adenocarcinomas induced by BHP in rats. Fifteen male Wistar rats, 6 weeks of age, were given 2000 ppm BHP in their drinking water for 12 weeks and then maintained without further treatment until sacrifice at 25 weeks, and 15 adenocarcinomas were obtained. Genomic DNAs were extracted from frozen tissues, and the LPA2, LPA3, LPA4 and LPA5 genes were examined for mutations, using polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis. No mutations of LPA2, LPA3, LPA4 and LPA5 were detected in the 15 adenocarcinomas. These results suggest that alterations due to LPA2, LPA3, LPA4 and LPA5 gene mutations might not be involved in the development of lung adenocarcinomas induced by BHP in rats. 相似文献
99.
Kessler SA Shimosato-Asano H Keinath NF Wuest SE Ingram G Panstruga R Grossniklaus U 《Science (New York, N.Y.)》2010,330(6006):968-971
During sexual reproduction in flowering plants such as Arabidopsis, a tip-growing pollen tube (PT) is guided to the synergid cells of the female gametophyte, where it bursts and releases the two sperm. Here we show that PT reception and powdery mildew (PM) infection, which involves communication between a tip-growing hypha and a plant epidermal cell, share molecular components. NORTIA (NTA), a member of the MLO family originally discovered in the context of PM resistance, and FERONIA (FER), a receptor-like kinase, both control PT reception in synergids. Homozygous fer mutants also display PM resistance, revealing a new function for FER and suggesting that conserved components, such as FER and distinct MLO proteins, are involved in both PT reception and PM infection. 相似文献
100.