全文获取类型
收费全文 | 147篇 |
免费 | 17篇 |
专业分类
164篇 |
出版年
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 7篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 6篇 |
2012年 | 14篇 |
2011年 | 12篇 |
2010年 | 4篇 |
2009年 | 8篇 |
2008年 | 4篇 |
2007年 | 12篇 |
2006年 | 12篇 |
2005年 | 12篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 4篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有164条查询结果,搜索用时 15 毫秒
61.
62.
Herranz R Husson D Pastor M Diaz C Mateos J Villa A Medina FJ Marco R 《Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology》2002,9(1):P357-P358
Our group has the long-term goal of establishing a permanent colony of Drosophila melanogaster in the International Space Station (ISS) to study its long-term adaptation to this unusual environment. We are currently building an enhanced version of an automatic cultivation unit (ESE1) in which we can grow flies with minimal crew involvement. We are working on a fixation unit as well. We are also adapting current protocols to maintain fixed animals during at least three months, the minimal refurbishment shuttle flight time, with minimal handling and maximal automatization, that can be used for inmuno-cytochemistry, ultrastructure or molecular experiments. 相似文献
63.
64.
Perier A Gourier C Pichard S Husson J Lajeunesse E Babon A Menez A Gillet D 《FEBS letters》2007,581(28):5480-5484
We describe the creation of cell adhesion mediated by cell surface engineering. The Flt3-ligand was fused to a membrane anchor made of the diphtheria toxin translocation domain. The fusion protein was attached to the surface of a cell by an acid pulse. Contact with another cell expressing the receptor Flt3 lead to its activation. This activity involved direct cell-cell contact. A mean force of 20 nN was needed to separate functionalized cells after 5 min of contact. Overall, we showed that it is possible to promote specific cell-cell adhesion by attaching protein ligands at the surface of cells. 相似文献
65.
Endogenous circadian clocks are inherent to all living organisms. They are needed to guarantee successful life since they regulate very important biological processes such as behavior and reproduction. Secretin-like G-protein coupled receptors are very important factors in the signal transduction pathways of circadian clocks. In this review, we will focus on the role of two secretin-like signaling pathways that play an important role in the regulation of the mammalian and the insect clock, respectively: the pituitary adenylate cyclase-activating polypeptide (PACAP) and pigment dispersing factor (PDF) signaling pathways. Both pathways are most likely related although their function in the biological clock differs. 相似文献
66.
67.
An in vitro method to determine the infectious potency of an unknown suspension of the protozoan parasite Toxoplasma gondii based on kinetics of host cells lysis was developed. Mic1-3KO a mutant strain of T. gondii RH tachyzoites was inoculated in 25-cm2 flasks containing a 90% confluent monolayer of human foreskin fibroblasts. Lysis kinetics was monitored for infection ratios ranging from 1∶10? to 1∶10; we defined 10? tachyzoites/ml?1 as the threshold value for parasite egress. Results allowed us to build a calibration curve relating the initial infection ratios to the time needed to reach 10? tachyzoites/ml?1. Finally, we validated the method using a known mixture of dead and live parasites. This method was found to estimate with accuracy the initial ratio of infection of the unknown parasite suspension. This easy-to-use method is reproducible and can be applied to any T. gondii tachyzoite RH strain, genetically modified or not. This method is also suitable for testing promising candidates for an effective live vaccine. 相似文献
68.
Justin Weaver Scott M. Husson Louise Murphy S. Ranil Wickramasinghe 《Biotechnology and bioengineering》2013,110(2):500-510
Anion exchange membrane adsorbers are used for contaminant removal in flow‐through polishing steps in the manufacture of biopharmaceuticals. This contribution describes the clearance of minute virus of mice, DNA, and host cell proteins by three commercially available anion‐exchange membranes: Sartobind Q, Mustang Q, and ChromaSorb. The Sartobind Q and Mustang Q products contain quaternary amine ligands; whereas, ChromaSorb contains primary amine based ligands. Performance was evaluated over a range of solution conditions: 0–200 mM NaCl, pH 6.0–9.0, and flow rates of 4–20 membrane volumes/min in the presence and absence of up to 50 mM phosphate and acetate. In addition contaminant clearance was determined in the presence and absence of 5 g/L monoclonal antibody. The quaternary amine based ligands depend mainly on Coulombic interactions for removal of negatively charged contaminants. Consequently, performance of Sartobind Q and Mustang Q was compromised at high ionic strength. Primary amine based ligands in ChromaSorb enable high capacities at high ionic strength due to the presence of secondary, hydrogen bonding interactions. However, the presence of hydrogen phosphate ions leads to reduced capacity. Monoclonal antibody recovery using primary amine based anion‐exchange ligands may be lower if significant binding occurs due to secondary interactions. The removal of a specific contaminant is affected by the level of removal of the other contaminants. The results of this study may be used to help guide selection of commercially available membrane absorbers for flow‐through polishing steps. Biotechnol. Bioeng. 2013; 110: 500–510. © 2012 Wiley Periodicals, Inc. 相似文献
69.
Disparity in Onset Timing and Frequency of Flowering and Fruiting Events in Two Bornean Peat‐Swamp Forests 下载免费PDF全文
Mark E. Harrison Nicole Zweifel Simon J. Husson Susan M. Cheyne Laura J. D'Arcy Fransiskus A. Harsanto Helen C. Morrogh‐Bernard Ari Purwanto Rahmatd Santiano Erin R. Vogel Serge A. Wich Maria A. van Noordwijk 《Biotropica》2016,48(2):188-197
The timing and frequency of flowering and fruiting events are key tropical forest characteristics that have substantial influence on fauna. Although our understanding of geographic variation in habitat‐wide timing and frequency of flowering and fruiting is advancing, corresponding information for individual tree species is limited. Thus, we compared climate and reproductive phenology of 16 tree species over 70 mo at two Bornean tropical peat‐swamp forest sites. We found significant inter‐site correlations in rainfall and temperature, and only small absolute temperature differences. In both sites, most species exhibited within‐site synchrony in flowering and fruiting onset. Broad‐scale flowering and fruiting onset frequency classifications showed high congruence between sites. Significant correlations in flowering and fruiting onset timing between sites were found for only 19 and 17 percent of the species, respectively. This remained the case when applying 1‐ and 2‐month lag periods for both sites, with neither site consistently lagging behind. Significant differences in the exact frequency of new flowering and fruiting events were detected for 44 and 58 percent of species, respectively, and no significant relationships between the onset timing synchrony and exact frequency of new reproductive events were found for either flowers or fruit. We conclude that inter‐site climatic and ecological similarities do not necessarily lead to high inter‐site synchrony in either onset timing or exact frequency of tree reproductive events. Potential reasons for this are discussed, as are the implications for understanding tropical forest ecology and improving forest restoration project seed collections. 相似文献
70.
How a single residue in individual β-thymosin/WH2 domains controls their functions in actin assembly
Didry D Cantrelle FX Husson C Roblin P Moorthy AM Perez J Le Clainche C Hertzog M Guittet E Carlier MF van Heijenoort C Renault L 《The EMBO journal》2012,31(4):1000-1013
β-Thymosin (βT) and WH2 domains are widespread, intrinsically disordered actin-binding peptides that display significant sequence variability and different regulations of actin self-assembly in motile and morphogenetic processes. Here, we reveal the structural mechanisms by which, in their 1:1 stoichiometric complexes with actin, they either inhibit assembly by sequestering actin monomers like Thymosin-β4, or enhance motility by directing polarized filament assembly like Ciboulot βT. We combined mutational, functional or structural analysis by X-ray crystallography, SAXS (small angle X-ray scattering) and NMR on Thymosin-β4, Ciboulot, TetraThymosinβ and the long WH2 domain of WASP-interacting protein. The latter sequesters G-actin with the same molecular mechanisms as Thymosin-β4. Functionally different βT/WH2 domains differ by distinct dynamics of their C-terminal half interactions with G-actin pointed face. These C-terminal interaction dynamics are controlled by the strength of electrostatic interactions with G-actin. At physiological ionic strength, a single salt bridge with actin located next to their central LKKT/V motif induces G-actin sequestration in both isolated long βT and WH2 domains. The results open perspectives for elucidating the functions of βT/WH2 domains in other modular proteins. 相似文献