全文获取类型
收费全文 | 299篇 |
免费 | 35篇 |
出版年
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 10篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 14篇 |
2014年 | 14篇 |
2013年 | 13篇 |
2012年 | 20篇 |
2011年 | 10篇 |
2010年 | 13篇 |
2009年 | 10篇 |
2008年 | 11篇 |
2007年 | 14篇 |
2006年 | 3篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 6篇 |
2000年 | 17篇 |
1999年 | 8篇 |
1998年 | 10篇 |
1997年 | 3篇 |
1996年 | 9篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 9篇 |
1990年 | 10篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1971年 | 2篇 |
1963年 | 1篇 |
排序方式: 共有334条查询结果,搜索用时 46 毫秒
321.
322.
Veronica Jausoro Berta E. Llorente Nancy M. Apóstolo 《Plant Cell, Tissue and Organ Culture》2010,101(2):183-191
The anatomy of normal and hyperhydric shoots (leaves and stems) of in vitro Handroanthus impetiginosus was compared using light microscopy, scanning electron microscopy, and transmission electron microscopy. In contrast to normal
shoots, hyperhydric shoots presented numerous anatomical abnormalities at the proliferation stage. Disorganized cortex, epidermal
holes, epidermal discontinuity, collapsed cells, and other structural characteristics were observed in hyperhydric shoots.
So, by using anatomical analysis of in vitro H. impetiginosus shoots at the proliferation stage, we can predict which plants will survive the rhizogenesis and acclimatization stages. 相似文献
323.
The cholinergic proteolipid from rat leg muscle, isolated by Sephadex LH-20 column chromatography, was purified about 5 fold further by affinity chromatography in organic solvents. The affinity column consisted of p-phenyltrimethylammonium as the active group and a pulse of acetylcholine or acid was used to desorb the specific fraction. From normal controls 36 μg of specific protein per g fresh tissue were obtained. In the denervated muscle there was no increase in this protein after three days, but it increased by 120% after six days. Binding studies carried out with 14C-acetylcholine, 3H-α-bungarotoxin and 14C-d-tubocurarine showed that only the specific fraction was able to bind the ligands. Three days after denervation the specific activity (nmoles/mg protein) for 14C-acetylcholine increased 400% and for 3H-α-bungarotoxin 100% over the control; on the contrary, there was no change in the binding of 14C-d-tubocurarine. These results are discussed in relation to the different pharmacological properties of the functional and extrajunctional receptors in skeletal muscle. 相似文献
324.
Stefano Burgio Everly Conway de Macario Alberto JL Macario Francesco Cappello 《Cell stress & chaperones》2021,26(4):611
A few reports suggest that molecular mimicry can have a role in determining the more severe and deadly forms of COVID-19, inducing endothelial damage, disseminated intravascular coagulation, and multiorgan failure. Heat shock proteins/molecular chaperones can be involved in these molecular mimicry phenomena. However, tumor cells can display on their surface heat shock proteins/molecular chaperones that are mimicked by SARS-CoV-2 molecules (including the Spike protein), similarly to what happens in other bacterial or viral infections. Since molecular mimicry between SARS-CoV-2 and tumoral proteins can elicit an immune reaction in which antibodies or cytotoxic cells produced against the virus cross-react with the tumor cells, we want to prompt clinical studies to evaluate the impact of SARS-CoV-2 infection on prognosis and follow up of various forms of tumors. These topics, including a brief historical overview, are discussed in this paper. 相似文献
325.
Garriga, N. and Llorente, G.A. 2011. Chondrocranial Ontogeny of Pelodytes punctatus (Anura: Pelodytidae). Response to competition: Geometric Morphometric and Allometric Change Analysis. —Acta Zoologica (Stockholm) 93 : 453–464. The chondrocranial development of Pelodytes punctatus is described, from tadpole to froglet, and compared with that of other taxa reported previously, such as species in the Pelobatidae, Pipidae, Ranidae, Hylidae, Bombinatoridae, Leptodactylidae, or Microhylidae families. The comparison leads us to suggest that the ontogeny of the anuran chondrocranium is very conservative, making it difficult to discern phylogenetic or ecologic patterns. Chondrocranial development is also analyzed to quantify shape changes and allometries during ontogeny, using linear and geometric morphometrics. The main shape change observed follows the general pattern of vertebrate postnatal development. The allometric analysis indicates the presence of different functional units in the chondrocranium that could be subjected to different pressures. Finally, tadpoles were raised in two conditions of competition to compare their chondrocranium development. The largest shape differences between the two conditions are located in the anterior region of the cranium and fit the general response to competition stress by increasing growth rate. Comparison of the scaling pattern between Pelodytes and Rana sylvatica and Bufo americanus shows differences, principally in the oral region, that do not fit with the general allometric pattern in larval anurans proposed in previous studies. 相似文献
326.
327.
328.
Expression of Mutant Dynamin Inhibits Toxicity and Transport of Endocytosed Ricin to the Golgi Apparatus 总被引:7,自引:0,他引:7 下载免费PDF全文
Alicia Llorente Andrzej Rapak Sandra L. Schmid Bo van Deurs Kirsten Sandvig 《The Journal of cell biology》1998,140(3):553-563
Endocytosis and intracellular transport of ricin were studied in stable transfected HeLa cells where overexpression of wild-type (WT) or mutant dynamin is regulated by tetracycline. Overexpression of the temperature-sensitive mutant dynG273D at the nonpermissive temperature or the dynK44A mutant inhibits clathrin-dependent endocytosis (Damke, H., T. Baba, A.M. van der Blieck, and S.L. Schmid. 1995. J. Cell Biol. 131: 69–80; Damke, H., T. Baba, D.E. Warnock, and S.L. Schmid. 1994. J. Cell Biol. 127:915–934). Under these conditions, ricin was endocytosed at a normal level. Surprisingly, overexpression of both mutants made the cells less sensitive to ricin. Butyric acid and trichostatin A treatment enhanced dynamin overexpression and increased the difference in toxin sensitivity between cells with normal and mutant dynamin. Intoxication with ricin seems to require toxin transport to the Golgi apparatus (Sandirg, K., and B. van Deurs. 1996. Physiol. Rev. 76:949–966), and this process was monitored by measuring the incorporation of radioactive sulfate into a modified ricin molecule containing a tyrosine sulfation site. The sulfation of ricin was much greater in cells expressing dynWT than in cells expressing dynK44A. Ultrastructural analysis using a ricin-HRP conjugate confirmed that transport to the Golgi apparatus was severely inhibited in cells expressing dynK44A. In contrast, ricin transport to lysosomes as measured by degradation of 125I-ricin was essentially unchanged in cells expressing dynK44A. These data demonstrate that although ricin is internalized by clathrin-independent endocytosis in cells expressing mutant dynamin, there is a strong and apparently selective inhibition of ricin transport to the Golgi apparatus. Also, in cells with mutant dynamin, there is a redistribution of the mannose-6-phosphate receptor. 相似文献
329.
Characterizing meiotic chromosomes' structure and pairing using a designer sequence optimized for Hi‐C 下载免费PDF全文
Nicolas Agier Aurèle Piazza Agnès Thierry Guillaume Mercy Stéphane Descorps‐Declere Luciana Lazar‐Stefanita Olivier Espeli Bertrand Llorente Gilles Fischer Julien Mozziconacci Romain Koszul 《Molecular systems biology》2018,14(7)
In chromosome conformation capture experiments (Hi‐C), the accuracy with which contacts are detected varies due to the uneven distribution of restriction sites along genomes. In addition, repeated sequences or homologous regions remain indistinguishable because of the ambiguities they introduce during the alignment of the sequencing reads. We addressed both limitations by designing and engineering 144 kb of a yeast chromosome with regularly spaced restriction sites (Syn‐HiC design). In the Syn‐HiC region, Hi‐C signal‐to‐noise ratio is enhanced and can be used to measure the shape of an unbiased distribution of contact frequencies, allowing to propose a robust definition of a Hi‐C experiment resolution. The redesigned region is also distinguishable from its native homologous counterpart in an otherwise isogenic diploid strain. As a proof of principle, we tracked homologous chromosomes during meiotic prophase in synchronized and pachytene‐arrested cells and captured important features of their spatial reorganization, such as chromatin restructuration into arrays of Rec8‐delimited loops, centromere declustering, individualization, and pairing. Overall, we illustrate the promises held by redesigning genomic regions to explore complex biological questions. 相似文献
330.