全文获取类型
收费全文 | 11121篇 |
免费 | 730篇 |
国内免费 | 1篇 |
出版年
2023年 | 103篇 |
2022年 | 188篇 |
2021年 | 401篇 |
2020年 | 292篇 |
2019年 | 375篇 |
2018年 | 421篇 |
2017年 | 418篇 |
2016年 | 570篇 |
2015年 | 750篇 |
2014年 | 714篇 |
2013年 | 792篇 |
2012年 | 919篇 |
2011年 | 887篇 |
2010年 | 567篇 |
2009年 | 470篇 |
2008年 | 588篇 |
2007年 | 535篇 |
2006年 | 503篇 |
2005年 | 378篇 |
2004年 | 337篇 |
2003年 | 309篇 |
2002年 | 240篇 |
2001年 | 193篇 |
2000年 | 147篇 |
1999年 | 122篇 |
1998年 | 65篇 |
1997年 | 34篇 |
1996年 | 41篇 |
1995年 | 27篇 |
1994年 | 33篇 |
1993年 | 30篇 |
1992年 | 47篇 |
1991年 | 32篇 |
1990年 | 30篇 |
1989年 | 20篇 |
1988年 | 34篇 |
1987年 | 25篇 |
1986年 | 23篇 |
1985年 | 25篇 |
1984年 | 12篇 |
1983年 | 10篇 |
1981年 | 11篇 |
1979年 | 15篇 |
1978年 | 14篇 |
1977年 | 9篇 |
1976年 | 10篇 |
1975年 | 10篇 |
1974年 | 10篇 |
1973年 | 8篇 |
1970年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Short‐term modern life‐like stress exacerbates Aβ‐pathology and synapse loss in 3xTg‐AD mice
下载免费PDF全文
![点击此处可从《Journal of neurochemistry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
993.
Reduced dopamine and glutamate neurotransmission in the nucleus accumbens of quinpirole‐sensitized rats hints at inhibitory D2 autoreceptor function
下载免费PDF全文
![点击此处可从《Journal of neurochemistry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
994.
Rodrigo Araújo Lima Rodrigues Ludmila Karen dos Santos Silva Fábio Pio Dornas Danilo Bretas de Oliveira Thais Furtado Ferreira Magalh?es Daniel Assis Santos Adriana Oliveira Costa Luiz de Macêdo Farias Paula Prazeres Magalh?es Cláudio Ant?nio Bonjardim Erna Geessien Kroon Bernard La Scola Juliana Reis Cortines J?natas Santos Abrah?o 《Journal of virology》2015,89(23):11812-11819
995.
Polyana C Tizioto Jeremy F Taylor Jared E Decker Caio F Gromboni Mauricio A Mudadu Robert D Schnabel Luiz L Coutinho Gerson B Mour?o Priscila SN Oliveira Marcela M Souza James M Reecy Renata T Nassu Flavia A Bressani Patricia Tholon Tad S Sonstegard Mauricio M Alencar Rymer R Tullio Ana RA Nogueira Luciana CA Regitano 《遗传、选种与进化》2015,47(1)
996.
Juliano D. Paccez Kristal Duncan Akhona Vava Ricardo G. Correa Towia A. Libermann M. Iqbal Parker Luiz F. Zerbini 《Molecular biology of the cell》2015,26(5):821-831
The receptor tyrosine kinase Axl has been described as an oncogene, and its deregulation has been implicated in the progression of several human cancers. While the role of Axl in esophageal adenocarcinoma has been addressed, there is no information about its role in esophageal squamous cell carcinoma (OSCC). In the current report, we identified, for the first time, deregulation of Axl expression in OSCC. Axl is consistently overexpressed in OSCC cell lines and human tumor samples, mainly in advanced stages of the disease. Blockage of Axl gene expression by small interfering RNA inhibits cell survival, proliferation, migration, and invasion in vitro and esophageal tumor growth in vivo. Additionally, repression of Axl expression results in Akt-dependent inhibition of pivotal genes involved in the nuclear factor-kappaB (NF-κB) pathway and in the induction of glycogen synthase kinase 3β (GSK3β) activity, resulting in loss of mesenchymal markers and induction of epithelial markers. Furthermore, treatment of esophageal cancer cells with the Akt inhibitor wortmannin inhibits NF-κB signaling, induces GSK3β activity, and blocks OSCC cell proliferation in an Axl-dependent manner. Taken together, our results establish a clear role for Axl in OSCC tumorigenesis with potential therapeutic implications. 相似文献
997.
Direct seeding of Brazilian savanna trees: effects of plant cover and fertilization on seedling establishment and growth
下载免费PDF全文
![点击此处可从《Restoration Ecology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Raíssa R. P. Silva Daniel R. Oliveira Gustavo P. E. da Rocha Daniel L. M. Vieira 《Restoration Ecology》2015,23(4):393-401
Direct seeding is a promising technique for ecological restoration, but it has been poorly studied in neotropical savannas. Different types of plant cover (no cover, crops, or green manure) and fertilization (unfertilized, synthetic fertilizer, or poultry litter) were used to verify if survival and growth of different tree species after direct seeding could be enhanced by the use of any combination of these techniques. Seedling emergence, establishment, and growth were followed for 2 years for six savanna tree species sown in an agricultural field in Central Brazil. Germination was high (52%, on average) for Anacardium occidentale, Aspidosperma macrocarpon, Hymenaea stigonocarpa, Dipteryx alata, Eugenia dysenterica, and Magonia pubescens. Six additional species were planted, but less than 5% of these seeds germinated. Crops (60% shade) did not affect seedling survival and biomass compared with the control treatment, supporting the use of this strategy during the initial phase of restoration to involve farmers in the process. In contrast, the excessive shading (95%) from the green manure treatment decreased the survival of two species and the growth in biomass and diameter of five species, especially when combined with fertilization. Seedling growth was very slow throughout the experiment, requiring extended weed management. This study supports the use of direct seeding of the studied species for savanna restoration, but methods could be improved to include a larger number of species. 相似文献
998.
Christoph Ott Henrik Martens Imam Hassouna Bárbara Oliveira Christian Erck Maria-Patapia Zafeiriou Ulla-Kaisa Peteri D?rte Hesse Simone Gerhart Bekir Altas Tekla Kolbow Herbert Stadler Hiroshi Kawabe Wolfram-Hubertus Zimmermann Klaus-Armin Nave Walter Schulz-Schaeffer Olaf Jahn Hannelore Ehrenreich 《Molecular medicine (Cambridge, Mass.)》2015,21(1):803-815
Erythropoietin (EPO) exerts potent neuroprotective, neuroregenerative and procognitive functions. However, unequivocal demonstration of erythropoietin receptor (EPOR) expression in brain cells has remained difficult since previously available anti-EPOR antibodies (EPOR-AB) were unspecific. We report here a new, highly specific, polyclonal rabbit EPOR-AB directed against different epitopes in the cytoplasmic tail of human and murine EPOR and its characterization by mass spectrometric analysis of immuno-precipitated endogenous EPOR, Western blotting, immunostaining and flow cytometry. Among others, we applied genetic strategies including overexpression, Lentivirus-mediated conditional knockout of EpoR and tagged proteins, both on cultured cells and tissue sections, as well as intracortical implantation of EPOR-transduced cells to verify specificity. We show examples of EPOR expression in neurons, oligodendroglia, astrocytes and microglia. Employing this new EPOR-AB with double-labeling strategies, we demonstrate membrane expression of EPOR as well as its localization in intracellular compartments such as the Golgi apparatus. Moreover, we show injury-induced expression of EPOR. In mice, a stereotactically applied stab wound to the motor cortex leads to distinct EpoR expression by reactive GFAP-expressing cells in the lesion vicinity. In a patient suffering from epilepsy, neurons and oligodendrocytes of the hippocampus strongly express EPOR. To conclude, this new analytical tool will allow neuroscientists to pinpoint EPOR expression in cells of the nervous system and to better understand its role in healthy conditions, including brain development, as well as under pathological circumstances, such as upregulation upon distress and injury. 相似文献
999.
α‐ l‐iduronidase gene‐based therapy using the phiC31 system to treat mucopolysaccharidose type I mice
下载免费PDF全文
![点击此处可从《The journal of gene medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Roberta Sessa Stilhano Priscila Keiko Matsumoto Martin Suely Maymone de Melo Vivian Yochiko Samoto Giovani Bravin Peres Yara Maria Correa da Silva Michelacci Flavia Helena da Silva Vanessa Gonçalves Pereira Vania D'Almeida Adriana Taveira da Cruz Miriam Galvonas Jasiulionis Sang Won Han 《The journal of gene medicine》2015,17(1-2):1-13
1000.
M. Ferreira Junior S.A. Batista P.V.T Vidigal A.A.C. Cordeiro F.M.S. Oliveira L.O. Prata A.E.T. Diniz C.M. Barral R.C. Barbuto A.D. Comes I.D. Araujo D.M.M. Queiroz M.V. Caliari 《European journal of histochemistry : EJH》2015,59(2)
Infection with Helicobacter pylori strains containing high number of EPIYA-C phosphorylation sites in the CagA is associated with significant gastritis and increased risk of developing pre-malignant gastric lesions and gastric carcinoma. However, these findings have not been reproduced in animal models yet. Therefore, we investigated the effect on the gastric mucosa of Mongolian gerbil (Meriones unguiculatus) infected with CagA-positive H. pylori strains exhibiting one or three EPIYA-C phosphorilation sites. Mongolian gerbils were inoculated with H. pylori clonal isolates containing one or three EPIYA-C phosphorylation sites. Control group was composed by uninfected animals challenged with Brucella broth alone. Gastric fragments were evaluated by the modified Sydney System and digital morphometry. Clonal relatedness between the isolates was considered by the identical RAPD-PCR profiles and sequencing of five housekeeping genes, vacA i/d region and of oipA. The other virulence markers were present in both isolates (vacA s1i1d1m1, iceA2, and intact dupA). CagA of both isolates was translocated and phosphorylated in AGS cells. After 45 days of infection, there was a significant increase in the number of inflammatory cells and in the area of the lamina propria in the infected animals, notably in those infected by the CagA-positive strain with three EPIYA-C phosphorylation sites. After six months of infection, a high number of EPIYA-C phosphorylation sites was associated with progressive increase in the intensity of gastritis and in the area of the lamina propria. Atrophy, intestinal metaplasia, and dysplasia were also observed more frequently in animals infected with the CagA-positive isolate with three EPIYA-C sites. We conclude that infection with H. pylori strain carrying a high number of CagA EPIYA-C phosphorylation sites is associated with more severe gastric lesions in an animal model of H. pylori infection.Key words: Gastritis, atrophy, intestinal metaplasia, dysplasia, Mongolian gerbil, cagA EPIYA C motif 相似文献