全文获取类型
收费全文 | 5234篇 |
免费 | 418篇 |
国内免费 | 1篇 |
出版年
2023年 | 24篇 |
2022年 | 51篇 |
2021年 | 124篇 |
2020年 | 56篇 |
2019年 | 87篇 |
2018年 | 104篇 |
2017年 | 94篇 |
2016年 | 160篇 |
2015年 | 292篇 |
2014年 | 281篇 |
2013年 | 374篇 |
2012年 | 453篇 |
2011年 | 433篇 |
2010年 | 268篇 |
2009年 | 205篇 |
2008年 | 340篇 |
2007年 | 321篇 |
2006年 | 285篇 |
2005年 | 281篇 |
2004年 | 270篇 |
2003年 | 232篇 |
2002年 | 247篇 |
2001年 | 53篇 |
2000年 | 43篇 |
1999年 | 48篇 |
1998年 | 56篇 |
1997年 | 55篇 |
1996年 | 21篇 |
1995年 | 39篇 |
1994年 | 36篇 |
1993年 | 41篇 |
1992年 | 29篇 |
1991年 | 18篇 |
1990年 | 17篇 |
1989年 | 22篇 |
1988年 | 17篇 |
1987年 | 10篇 |
1986年 | 13篇 |
1985年 | 16篇 |
1984年 | 11篇 |
1983年 | 8篇 |
1982年 | 19篇 |
1981年 | 12篇 |
1980年 | 7篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1976年 | 10篇 |
1975年 | 7篇 |
1973年 | 7篇 |
1969年 | 11篇 |
排序方式: 共有5653条查询结果,搜索用时 15 毫秒
901.
Control of Pratylenchus brachyurus in soybean with Trichoderma spp. and resistance inducers 下载免费PDF全文
Juliana Kath Cláudia R. Dias‐Arieira Júlio César Antunes Ferreira Juliana Aparecida Homiak Camila Rocco da Silva Carine Rezende Cardoso 《Journal of Phytopathology》2017,165(11-12):791-799
Trichoderma spp. is a fungus with nematode control potential; however, its potential to control the root lesion nematode Pratylenchus brachyurus remains poorly studied. Thus, the aim of this study was to select Trichoderma spp. isolates and assess their ability to control P. brachyurus in soybean crops. Different experiments were conducted aiming at selecting isolates, assessing whether they were able to reduce nematode penetration in plants or cause mortality in vitro, and whether they were able to induce resistance in soybean, as well as at studying the possibility of using the selected isolates associated with resistance inducers (acibenzolar‐S‐methyl, Ecolife? and AgroMos?). The selection experiment found three isolates showing satisfactory results, namely GF422, GF425 and GF427; the GF362 isolate was assessed in the subsequent experiments. These four isolates reduced P. brachyurus penetration in soybean roots and promoted nematode mortality in vitro. Increased total protein and catalase activity were recorded, mainly in the 72‐hr assessments. Overall, the protein production was different between isolates. The best results were found in the combination between the GF362 isolate and the three resistance inducers, between GF427 and Ecolife?, between GF427 and AgroMos? and between GF422 and Ecolife?. 相似文献
902.
Identification of aminopyrimidine‐sulfonamides as potent modulators of Wag31‐mediated cell elongation in mycobacteria 下载免费PDF全文
János Pató Gaëlle S. Kolly Jana Korduláková Martin Forbak Joanna C. Evans Rita Székely Jan Rybniker Zuzana Palčeková Júlia Zemanová Isabella Santi François Signorino‐Gelo Liliana Rodrigues Anthony Vocat Adrian S. Covarrubias Monica G. Rengifo Kai Johnsson Sherry Mowbray Joseph Buechler Vincent Delorme Priscille Brodin Graham W. Knott José A. Aínsa Digby F. Warner Katarína Mikušová John D. McKinney Ruben C. Hartkoorn 《Molecular microbiology》2017,103(1):13-25
903.
HOTAIR role in melanoma progression and its identification in the blood of patients with advanced disease 下载免费PDF全文
904.
905.
Nouha Ben-Othman Andhira Vieira Monica Courtney Fabien Record Elisabet Gjernes Fabio Avolio Biljana Hadzic Noémie Druelle Tiziana Napolitano Sergi Navarro-Sanz Serena Silvano Keith Al-Hasani Anja Pfeifer Sandra Lacas-Gervais Gunter Leuckx Laura Marroquí Julien Thévenet Ole Dragsbaek Madsen Patrick Collombat 《Cell》2017,168(1-2):73-85.e11
906.
Cytological analysis with respect to meiotic behaviour is considered to be the one of the most dependable indices to estimate the potency of mutagens and to elucidate the response of various genotypes to a particular mutagen. Seeds of Lablab purpureus (L.) Sweet var. typicus cv. CO(Gb)14 were subjected to different doses/concentrations of gamma rays and EMS. The effects of different mutagenic treatments on meiosis were studied on treated and control plants. Various types of meiotic aberrations such as stickiness, clumping of chromosomes, laggards, ring chromosomes and precocious movements were observed in the mutagenic treatments. As increase in the concentration, the frequency of cells showing chromosomal aberrations shows a linear increase up to a certain level. However, the EMS treatments proved to be more effective in inducing meiotic aberrations as compared to gamma rays. 相似文献
907.
Florin G. Horhat Fuat Gundogdu Laurentiu V. David Eugen S. Boia Laurentiu Pirtea Razvan Horhat Alexandru Cucui-Cozma Ioana Ciuca Mircea Diaconu Razvan Nitu Monica Licker Delia I. Horhat Alexandru F. Rogobete Marius L. Moise Calin Tataru 《Biochemical genetics》2017,55(3):204-211
A high percentage of critical patients are found to develop acute respiratory distress syndrome (ARDS). Several studies have reported high mortality rates in these cases which are most frequently associated with multiple organ dysfunctions syndrome. Lately, many efforts have been made to evaluate and monitor ARDS in critical patients. In this regard, the assessment of genetic polymorphisms responsible for developing ARDS present as a challenge and are considered future biomarkers. Early detection of the specific polymorphic gene responsible for ARDS in critically ill patients can prove to be a useful tool in the future, able to help decrease the mortality rates in these cases. Moreover, identifying the genetic polymorphism in these patients can help in the implementation of a personalized intensive therapy scheme for every type of patient, based on its genotype. 相似文献
908.
Carlo Pinna Carla Giuditta Vecchiato Vladimiro Cardenia Maria Teresa Rodriguez-Estrada Claudio Stefanelli Monica Grandi 《Archives of animal nutrition》2017,71(5):395-412
The in vitro effect of a Yucca schidigera extract (YSE) and tannins from chestnut wood on composition and metabolic activity of canine and feline faecal microbiota was evaluated. Four treatments were carried out: control diet, chestnut tannins (CT), YSE and CT + YSE. The YSE was added to canine and feline faecal cultures at 0.1 g/l, while CT were added at 0.3 g/l for a 24-h incubation. A total of 130 volatile compounds were detected by means of headspace-solid phase microextraction gas-chromatography/mass spectrometry analyses. Several changes in the metabolite profiles of fermentation fluids were found, including a decrease of alcohols (?19%) and esters (?42%) in feline and canine inoculum, respectively, which was due to the antibacterial properties of tannins. In canine inoculum, after 6 h, YSE + CT caused lower cadaverine concentrations (?37%), while ammonia (?4%) and quinolone (?27%) were reduced by addition of CT. After 24 h, the presence of CT resulted in a decrease of sulphur compounds, such as dimethyl sulphide (?69%) and dimethyl disulphide (?20%). In feline faecal cultures, after 6 h, CT lowered the amount of indole (?48%), whereas YSE tended to decrease trimethylamine levels (?16%). Both in canine and feline inoculum, addition of CT and, to a minor extent, YSE affected volatile fatty acids patterns. In canine faecal cultures, CT exerted a marginal inhibitory effect on Escherichia coli population (?0.45 log 10 numbers of DNA copies/ml), while enterococci were increased (+2.06 log 10 numbers of DNA copies/ml) by YSE. The results from the present study show that YSE and tannins from chestnut wood exert different effects on the composition and metabolism of canine and feline faecal microbiota. In particular, the supplementation of YSE and tannins to diets for dogs and cats may be beneficial due to the reduction of the presence of some potentially toxic volatile metabolites in the animals’ intestine. 相似文献
909.
This paper identifies two difficulties with treatments of derivation in Algonquian languages. In traditional approaches to grammar, in which the morpheme is seen as a unitary entity, morphemes are understood as minimal units of meaning and/or function. Definitions share an appeal to the morpheme’s indivisibility. In the Algonquianist literature, in contrast, some morphemes (‘components’) can themselves contain other morphemes (which we call ‘formatives’) and they can also be synchronically derived from other components or stems. Drawing data from Menominee, we propose that these difficulties disappear if the formatives are seen as historical rather than synchronic units, while the components are the synchronic morphemes. Formatives bear the hallmarks of historical products of morphologization (phonetic/phonological reduction, semantic bleaching, and increase in grammatical function), and we conclude that they are not part of synchronic grammatical computation. This resolves problems present in traditional and modern theoretical approaches to Algonquian derivation, and has broader ramifications for linguistic theory: in both the structuralist and generativist traditions, synchronic grammar has often been seen as expansive, responsible for generating surface patterns that may instead be products of history. This has been the case in phonology and syntax. The present paper provides a study of the phenomenon in derivational morphology, and suggests that a more modest role for synchronic rules is called for. 相似文献
910.