全文获取类型
收费全文 | 548篇 |
免费 | 59篇 |
国内免费 | 2篇 |
出版年
2023年 | 6篇 |
2022年 | 2篇 |
2021年 | 9篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 9篇 |
2017年 | 7篇 |
2016年 | 22篇 |
2015年 | 23篇 |
2014年 | 30篇 |
2013年 | 30篇 |
2012年 | 38篇 |
2011年 | 48篇 |
2010年 | 29篇 |
2009年 | 16篇 |
2008年 | 32篇 |
2007年 | 35篇 |
2006年 | 39篇 |
2005年 | 27篇 |
2004年 | 34篇 |
2003年 | 39篇 |
2002年 | 34篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 11篇 |
1997年 | 4篇 |
1995年 | 2篇 |
1994年 | 7篇 |
1993年 | 2篇 |
1991年 | 4篇 |
1988年 | 3篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1983年 | 2篇 |
1979年 | 3篇 |
1975年 | 3篇 |
1971年 | 1篇 |
1964年 | 1篇 |
1959年 | 1篇 |
1958年 | 3篇 |
1957年 | 2篇 |
1955年 | 3篇 |
1954年 | 2篇 |
1953年 | 2篇 |
1952年 | 2篇 |
1951年 | 4篇 |
1950年 | 2篇 |
1949年 | 1篇 |
1948年 | 1篇 |
排序方式: 共有609条查询结果,搜索用时 15 毫秒
581.
582.
583.
584.
585.
Lipid transport proteins at membrane contact sites, where two organelles are closely apposed, play key roles in trafficking lipids between cellular compartments while distinct membrane compositions for each organelle are maintained. Understanding the mechanisms underlying non‐vesicular lipid trafficking requires characterization of the lipid transporters residing at contact sites. Here, we show that the mammalian proteins in the lipid transfer proteins anchored at a membrane contact site (LAM) family, called GRAMD1a‐c, transfer sterols with similar efficiency as the yeast orthologues, which have known roles in sterol transport. Moreover, we have determined the structure of a lipid transfer domain of the yeast LAM protein Ysp2p, both in its apo‐bound and sterol‐bound forms, at 2.0 Å resolution. It folds into a truncated version of the steroidogenic acute regulatory protein‐related lipid transfer (StART) domain, resembling a lidded cup in overall shape. Ergosterol binds within the cup, with its 3‐hydroxy group interacting with protein indirectly via a water network at the cup bottom. This ligand binding mode likely is conserved for the other LAM proteins and for StART domains transferring sterols. 相似文献
586.
587.
Jodi Hirschman Tanya Z. Berardini Harold J. Drabkin Doug Howe 《Molecular genetics and genomics : MGG》2010,283(5):415-425
Curation of biological data is a multi-faceted task whose goal is to create a structured, comprehensive, integrated, and accurate
resource of current biological knowledge. These structured data facilitate the work of the scientific community by providing
knowledge about genes or genomes and by generating validated connections between the data that yield new information and stimulate
new research approaches. For the model organism databases (MODs), an important source of data is research publications. Every
published paper containing experimental information about a particular model organism is a candidate for curation. All such
papers are examined carefully by curators for relevant information. Here, four curators from different MODs describe the literature
curation process and highlight approaches taken by the four MODs to address: (1) the decision process by which papers are
selected, and (2) the identification and prioritization of the data contained in the paper. We will highlight some of the
challenges that MOD biocurators face, and point to ways in which researchers and publishers can support the work of biocurators
and the value of such support. 相似文献
588.
In shells of the oysters Exogyra cancellata and Pycnodonte mutabilis from the Mount Laurel and Marshalltown Formations (Campanian‐Maestrichtian), three‐quarters of all valves bear sponge borings (Entobia isp.) borings and 30% have borings of a lithophagid bivalve (Gastrochaenolites isp.). Non‐random distributions of these euendoliths, documented in this paper, may in part be accounted for by differential survival of sponge and lithophagid larvae and spat in varying circumstances. In addition, exterior shell architectures and post‐mortem orientations of shells are inferred to have prompted active geophobic (antigravity), rugophilic (groove‐seeking), and rheophilic (current‐seeking) behavior that enhanced survivorship of the settling larvae. 相似文献
589.
A reciprocal transplant experiment was conducted to uncouple genetic and environmental effects on plant fitness of a range-expanding indigenous shrub, Leptospermum scoparium . Patterns of encroachment differed significantly between three regions of Eucalyptus camaldulensis woodland in the Grampians National Park, south-eastern Australia, with greater shrub densities found in the Victoria Valley region. Higher shrub densities in this region are likely due to greater fruit production/shrub, increased field germination and increased early seedling survival. The results of the reciprocal transplant experiment showed increased fitness appears to be due to phenotypic plasticity in response to favourable environmental conditions rather than genotypic variation. Field germination and seedling survival were influenced by region of planting and not seed origin. However, differences in shoot length and biomass of seedlings between the regions were detected after five months of growth in uniform conditions which may indicate genetic differentiation. The results, however, suggest range expansion is partly due to increased plant fitness which is likely a plastic response to favourable environmental conditions, especially soil moisture. 相似文献
590.
Matthieu Keller Jodi L. Pawluski Olivier Brock Quentin Douhard Julie Bakker 《Hormones and behavior》2010,57(4-5):434-440
In rodent species, sexual differentiation of the brain for many reproductive processes depends largely on estradiol. This was recently confirmed again by using the α-fetoprotein knockout (AFP-KO) mouse model, which lacks the protective actions of α-fetoprotein against maternal estradiol and as a result represents a good model to determine the contribution of prenatal estradiol to the sexual differentiation of the brain and behavior. Female AFP-KO mice were defeminized and masculinized with regard to their neuroendocrine responses as well as sexual behavior. Since parental behavior is also strongly sexually differentiated in mice, we used the AFP-KO mouse model here to ask whether parental responses are differentiated prenatally under the influence of estradiol. It was found that AFP-KO females showed longer latencies to retrieve pups to the nest and also exhibited lower levels of crouching over the pups in the nest in comparison to WT females. In fact, they resembled males (WT and AFP-KO). Other measures of maternal behavior, for example the incidence of infanticide, tended to be higher in AFP-KO females than in WT females but this increase failed to reach statistical significance. The deficits observed in parental behavior of AFP-KO females could not be explained by any changes in olfactory function, novelty recognition or anxiety. Thus our results suggest that prenatal estradiol defeminizes the parental brain in mice. 相似文献