全文获取类型
收费全文 | 1520篇 |
免费 | 17篇 |
国内免费 | 1篇 |
出版年
2015年 | 8篇 |
2014年 | 6篇 |
2013年 | 36篇 |
2012年 | 26篇 |
2011年 | 40篇 |
2010年 | 68篇 |
2009年 | 60篇 |
2008年 | 61篇 |
2007年 | 91篇 |
2006年 | 58篇 |
2005年 | 61篇 |
2004年 | 30篇 |
2003年 | 15篇 |
2001年 | 18篇 |
2000年 | 17篇 |
1999年 | 20篇 |
1998年 | 44篇 |
1997年 | 42篇 |
1996年 | 32篇 |
1995年 | 36篇 |
1994年 | 32篇 |
1993年 | 33篇 |
1992年 | 25篇 |
1991年 | 50篇 |
1990年 | 26篇 |
1989年 | 40篇 |
1988年 | 27篇 |
1987年 | 31篇 |
1986年 | 18篇 |
1985年 | 32篇 |
1984年 | 31篇 |
1983年 | 22篇 |
1982年 | 11篇 |
1981年 | 22篇 |
1980年 | 19篇 |
1979年 | 32篇 |
1978年 | 16篇 |
1977年 | 19篇 |
1976年 | 25篇 |
1975年 | 33篇 |
1974年 | 21篇 |
1973年 | 20篇 |
1972年 | 37篇 |
1971年 | 38篇 |
1970年 | 11篇 |
1969年 | 7篇 |
1968年 | 9篇 |
1967年 | 7篇 |
1952年 | 7篇 |
1951年 | 6篇 |
排序方式: 共有1538条查询结果,搜索用时 62 毫秒
1.
JANEY HENDERSON HEATHER MACDONALD COLIN M. LAZARUS RICHARD M. NAPIER CHRIS R. HAWES 《Cell biology international》1996,20(6):413-422
High level expression of the major auxin-binding protein (ABP1) from maize (Zea maysL.) has been used to demonstrate that the machinery for retaining proteins in the endoplasmic reticulum (ER) of insect cells functions efficiently throughout the baculovirus infection cycle. Immuno-localization showed wild-type ABP1 (ABP1-KDEL) to be targeted to the lumen of the ER, in accordance with its signal peptide and carboxyterminal KDEL ER-retention signal. The protein accumulated in dilations of the ER, and none was detected at the cell surface. Immunoblotting of concentrated culture medium confirmed that ABP1-KDEL was not secreted at a detectable level. In contrast, when the carboxyterminus was mutated to KEQL, secretion of the baculovirus-expressed protein was readily detected. Immunolocalization and immunoblotting demonstrated that a high proportion of the ABP1-KEQL protein was secreted at the cell surface and into the culture medium. The data demonstrate that the ER of insect cells has a great capacity to retain proteins and that this property is largely unaffected by the cellular disruption caused by baculovirus replication. 相似文献
2.
3.
DAVID L. BRAFF TIFFANY A. GREENWOOD NEAL R. SWERDLOW GREGORY A. LIGHT NICHOLAS J. SCHORK The Investigators of the Consortium on the Genetics of Schizophrenia 《World psychiatry》2008,7(1):11-18
The search for the genetic architecture of schizophrenia has employed multiple, often converging strategies. One such strategy entails the use of tracing the heritability and neurobiology of endophenotypes. Endophenotypes are quantifiable traits not visible to the eye, which are thought to reflect an intermediate place on the path from genes to disorder. Endophenotype abnormalities in domains such as neurophysiology or neurocognition occur in schizophrenia patients as well as their clinically “unaffected” relatives, and reflect polymorphisms in the DNA of schizophrenia spectrum subjects which create vulnerability to developing schizophrenia. By identifying the single nucleotide polymorphisms (SNPs) associated with endophenotypes in schizophrenia, psychiatric neuroscientists can select new strong inference based molecular targets for the treatment of schizophrenia. 相似文献
4.
FIONA J. QUALLS RICHARD SHINE 《Biological journal of the Linnean Society. Linnean Society of London》2000,71(2):315-341
While recent experimental work on a variety of reptile species has demonstrated that incubation temperature influences hatchling phenotypes, the biological significance of such phenotypic variation remains unclear. Incubation temperature may exert significant long-term phenotypic effects. Alternatively, such influences may be temporary, or negligible relative to effects induced by genetic factors, or by the environmental conditions experienced after hatching. Even if incubation temperature exerts long-term effects on phenotype, this might occur indirectly (by influencing hatching dates) rather than by direct modifications of developmental processes. We quantified the influences of the source population, incubation temperature and rearing environment, on the phenotype of the Australian garden skink (Lampropholis guichenoti) from populations that differ in nest temperature and phenotype. Intcrpopulation differences in the phenotypes of young lizards were found to be a product of all three factors. However, the long-term effects of both population and incubation temperature operated indirectly (through variation in the date of hatching) rather than directly (through genetic or developmental factors). That is, once all temporal effects were removed, the only discernible influence on juvenile phenotypes was their rearing environment. Thus, some of the most important influences on lizard phenotypes may operate via modifications of hatching date. 相似文献
5.
RACHAEL HICKLING † DAVID B. ROY JANE K. HILL† RICHARD FOX‡ CHRIS D. THOMAS† 《Global Change Biology》2006,12(3):450-455
Evidence is accumulating of shifts in species' distributions during recent climate warming. However, most of this information comes predominantly from studies of a relatively small selection of taxa (i.e., plants, birds and butterflies), which may not be representative of biodiversity as a whole. Using data from less well‐studied groups, we show that a wide variety of vertebrate and invertebrate species have moved northwards and uphill in Britain over approximately 25 years, mirroring, and in some cases exceeding, the responses of better‐known groups. 相似文献
6.
Novel strategies for assessing and managing the risks posed by invasive alien species to global crop production and biodiversity 总被引:3,自引:0,他引:3
RICHARD BAKER RAY CANNON PAUL BARTLETT IAN BARKER 《The Annals of applied biology》2005,146(2):177-191
International actions to combat the threat posed by invasive alien species (IAS) to crops and biodiversity have intensified in recent years. The formulation of 15 guiding principles on IAS by the Convention on Biological Diversity (CBD) stimulated the International Plant Protection Convention (IPPC) to review its role in protecting biodiversity. IPPC standards now demonstrate clearly that the risks posed by any organism that is directly or indirectly injurious to cultivated or uncultivated plants can be assessed and managed under the IPPC. Since the IPPC, unlike the CBD, constitutes an international legal instrument recognised by the World Trade Organization, greater protection from the introduction of IAS is now available. However, phytosanitary measures can only be enacted if they can be justified by risk analysis and we outline some novel strategies to improve the assessment and management of the risks posed by IAS, highlighting some of the key challenges which remain. 相似文献
7.
The incidence of the parasitic disease trichomoniasis and its treatment in reintroduced and wild Pink Pigeons Columba mayeri 总被引:1,自引:0,他引:1
The recovery programme for the endangered Pink Pigeon Columba mayeri Prévost, 1843 of Mauritius has involved intensive management to promote rapid population growth. As the Pink Pigeon population has increased in size and distribution, disease problems have emerged that have affected wild and reintroduced birds. Trichomoniasis first appeared in the remnant wild population in 1992, and became established in a reintroduced subpopulation on the offshore island of Ile aux Aigrettes. We aimed to control the disease by treating individuals and, on Ile aux Aigrettes, by routinely treating the population with medicated drinking water. On Ile aux Aigrettes, 49% of squabs were clinically diseased and only 27% of all squabs survived without treatment. Treatment of squabs that were not clinically diseased improved survival from 36 to 82%, suggesting that subclinical infections also affected survival. Subclinical infections were demonstrated by microscopy in 22% of Pink Pigeons and 17% of exotic doves on Ile aux Aigrettes. Clinical disease was observed in 4.5% of adults and 3.1% of juveniles, but more juveniles than adults died from the disease. It is likely that Trichomoniasis and other diseases will continue to affect the Pink Pigeon's recovery and the species may require long-term management to counteract the effects of disease and other limiting factors. 相似文献
8.
9.
10.