全文获取类型
收费全文 | 328篇 |
免费 | 17篇 |
专业分类
345篇 |
出版年
2022年 | 5篇 |
2021年 | 11篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 2篇 |
2013年 | 14篇 |
2012年 | 15篇 |
2011年 | 19篇 |
2010年 | 12篇 |
2009年 | 11篇 |
2008年 | 16篇 |
2007年 | 12篇 |
2006年 | 18篇 |
2005年 | 9篇 |
2004年 | 12篇 |
2003年 | 17篇 |
2002年 | 9篇 |
2001年 | 4篇 |
2000年 | 11篇 |
1999年 | 6篇 |
1997年 | 2篇 |
1991年 | 10篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 7篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1974年 | 6篇 |
1973年 | 6篇 |
1972年 | 7篇 |
1971年 | 6篇 |
1969年 | 5篇 |
1968年 | 4篇 |
1967年 | 3篇 |
1966年 | 4篇 |
1965年 | 3篇 |
1951年 | 3篇 |
1950年 | 1篇 |
排序方式: 共有345条查询结果,搜索用时 0 毫秒
201.
202.
MARIE‐NOËLLE VAULTIER MARIE‐PAULE HASENFRATZ‐SAUDER DIDIER LE THIEC PIERRE DIZENGREMEL GRAHAM NOCTOR YVES JOLIVET 《Plant, cell & environment》2013,36(11):1981-1991
Oxidative stress caused by ozone (O3) affects plant development, but the roles of specific redox‐homeostatic enzymes in O3 responses are still unclear. While growth day length may affect oxidative stress outcomes, the potential influence of day length context on equal‐time exposures to O3 is not known. In Arabidopsis Col‐0, day length affected the outcome of O3 exposure. In short‐days (SD), few lesions were elicited by treatments that caused extensive lesions in long days (LD). Lesion formation was not associated with significant perturbation of glutathione, ascorbate, NADP(H) or NAD(H). To investigate roles of two genes potentially underpinning this redox stability, O3 responses of mutants for cytosolic NADP‐isocitrate dehydrogenase (icdh) and glutathione reductase 1 (gr1) were analysed. Loss of ICDH function did not affect O3‐induced lesions, but slightly increased glutathione oxidation, induction of other cytosolic NADPH‐producing enzymes and pathogenesis‐related gene 1 (PR1). In gr1, O3‐triggered lesions, salicylic acid accumulation, and induction of PR1 were all decreased relative to Col‐0 despite enhanced accumulation of glutathione. Thus, even at identical irradiance and equal‐time exposures, day length strongly influences phenotypes triggered by oxidants of atmospheric origin, while in addition to its antioxidant function, the GR‐glutathione system seems to play novel signalling roles during O3 exposure. 相似文献
203.
GUILLERMO H. CASSINI MANUEL MENDOZA SERGIO F. VIZCAÍNO M. SUSANA BARGO 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2011,44(2):153-165
Cassini, G.H., Mendoza, M., Vizcaíno, S.F. & Bargo, M.S. 2011: Inferring habitat and feeding behaviour of early Miocene notoungulates from Patagonia. Lethaia, Vol. 44, pp. 153–165. Notoungulates, native fossil mammals of South America, have been usually studied from a taxonomic point of view, whereas their palaeobiology has been largely neglected. For example, morpho‐functional or eco‐morphological approaches have not been rigorously applied to the masticatory apparatus to propose hypothesis on dietary habits. In this study, we generate inferences about habitat and feeding preferences in five Santacrucian genera of notoungulates of the orders Typotheria and Toxodontia using novel computer techniques of knowledge discovery. The Santacrucian (Santa Cruz Formation, late‐early Miocene) fauna is particularly appropriate for this kind of studies due to its taxonomic richness, diversity, amount of specimens recorded and the quality of preservation. Over 100 extant species of ungulates, distributed among 13 families of artiodactyls and perissodactyls, were used as reference samples to reveal the relationships between craniodental morphology and ecological patterns. The results suggest that all Santacrucian notoungulates present morphologies characteristic of open habitats’ extant ungulates. Although the Toxodontia exhibits the same morphological pattern of living mixed‐feeders and grazers, the Typotheria shows exaggerated traits of specialized grazer ungulates. □Craniodental morphology, ecomorphology, fossil ungulates, knowledge discovery, South America. 相似文献
204.
Yu. Yu. Silaeva A. A. Kalinina M. S. Vagida L. M. Khromykh A. V. Deikin T. G. Ermolkevich E. R. Sadchikova I. L. Goldman D. B. Kazansky 《Biochemistry. Biokhimii?a》2013,78(5):549-559
Peripheral T lymphocytes can be subdivided into naive and antigen-experienced T cells. The latter, in turn, are represented by effector and central memory cells that are identified by different profiles of activation markers expression, such as CD44 and CD62L in mice. These markers determine different traffic of T lymphocytes in the organism, but hardly reproduce real antigenic experience of a T lymphocyte. Mechanisms of homeostasis maintenance of T lymphocytes with different activation phenotypes remain largely unknown. To investigate impact of T cell receptor (TCR) transgenic chains on formation of T lymphocytes, their peripheral survival and activation surface phenotypes, we have generated the transgenic mouse strain expressing transgenic β-chain of TCR 1D1 (belonging to the Vβ6 family) on the genetic background B10.D2(R101). Intrathymic development of T cells in these transgenic mice is not impaired. The repertoire of peripheral T lymphocytes in these mice contains 70–80% of T cells expressing transgenic β-chain and 20–30% of T cells expressing endogenous β-chains. The ratio of peripheral CD4+CD8? and CD4?CD8+ T lymphocytes remained unchanged in the transgenic animals, but the percent of T lymphocytes with the “naive” phenotype CD44?CD62L+ was significantly increased, whereas the levels of effector memory CD44+CD62L? and central memory CD44+CD62L+ T lymphocytes were markedly decreased in both subpopulations. On the contrary, T lymphocytes expressing endogenous β-chains had surface phenotype of activated T cells CD44+. Thus, for the first time we have shown that the pool of T lymphocytes with different activation phenotypes depends on the structure of T cell receptors. 相似文献
205.
Khromov A. V. Makhotenko A. V. Makarova S. S. Suprunova T. P. Kalinina N. O. Taliansky M. E. 《Russian Journal of Bioorganic Chemistry》2020,46(6):1242-1249
Russian Journal of Bioorganic Chemistry - Genome editing using the CRISPR/Cas9 system is an innovation platform exploiting site-specific nuclease to create modifications (deletions or insertions)... 相似文献
206.
Pogorelov A. G. Makarova N. P. Kalinina E. A. Panait A. I. Pogorelova V. N. Sukhih G. T. 《Doklady. Biochemistry and biophysics》2021,498(1):190-192
Doklady Biochemistry and Biophysics - For in vitro fertilization technology, the quality of oocytes has a direct impact on the egg fertilization and developmental competence of early embryo. The... 相似文献
207.
Igor Fesenko Nadezhda Spechenkova Anna Mamaeva Antonida V. Makhotenko Andrew J. Love Natalia O. Kalinina Michael Taliansky 《Molecular Plant Pathology》2021,22(1):77-91
Plant–virus interactions are greatly influenced by environmental factors such as temperatures. In virus-infected plants, enhanced temperature is frequently associated with more severe symptoms and higher virus content. However, the mechanisms involved in such regulatory effects remain largely uncharacterized. To provide more insight into the mechanisms whereby temperature regulates plant–virus interactions, we analysed changes in the proteome of potato cv. Chicago plants infected with potato virus Y (PVY) at normal (22 °C) and elevated temperature (28 °C), which is known to significantly increase plant susceptibility to the virus. One of the most intriguing findings is that the main enzymes of the methionine cycle (MTC) were down-regulated at the higher but not at normal temperatures. With good agreement, we found that higher temperature conditions triggered consistent and concerted changes in the level of MTC metabolites, suggesting that the enhanced susceptibility of potato plants to PVY at 28 °C may at least be partially orchestrated by the down-regulation of MTC enzymes and concomitant cycle perturbation. In line with this, foliar treatment of these plants with methionine restored accumulation of MTC metabolites and subverted the susceptibility to PVY at elevated temperature. These data are discussed in the context of the major function of the MTC in transmethylation processes. 相似文献
208.
Sorokin Ivan I. Vassilenko Konstantin S. Terenin Ilya M. Kalinina Natalia O. Agol Vadim I. Dmitriev Sergey E. 《Biochemistry. Biokhimii?a》2021,86(9):1060-1094
Biochemistry (Moscow) - Viruses exploit the translation machinery of an infected cell to synthesize their proteins. Therefore, viral mRNAs have to compete for ribosomes and translation factors with... 相似文献
209.
210.