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71.
Edenfeld G Volohonsky G Krukkert K Naffin E Lammel U Grimm A Engelen D Reuveny A Volk T Klämbt C 《Neuron》2006,52(6):969-980
In both vertebrates and invertebrates, glial cells wrap axonal processes to ensure electrical conductance. Here we report that Crooked neck (Crn), the Drosophila homolog of the yeast Clf1p splicing factor, is directing peripheral glial cell maturation. We show that crooked neck is expressed and required in glial cells to control migration and axonal wrapping. Within the cytoplasm, Crn interacts with the RNA-binding protein HOW and then translocates to the nucleus where the Crn/HOW complex controls glial differentiation by facilitating splicing of specific target genes. By using a GFP-exon trap approach, we identified some of the in vivo target genes that encode proteins localized in autocellular septate junctions. In conclusion, here we show that glial cell differentiation is controlled by a cytoplasmic assembly of splicing components, which upon translocation to the nucleus promote the splicing of genes involved in the assembly of cellular junctions. 相似文献
72.
DeNinno MP Masamune H Chenard LK DiRico KJ Eller C Etienne JB Tickner JE Kennedy SP Knight DR Kong J Oleynek JJ Tracey WR Hill RJ 《Bioorganic & medicinal chemistry letters》2006,16(9):2525-2527
Using a combination of parallel and directed synthesis, the discovery of a highly potent and selective series of adenosine A3 agonists was achieved. High aqueous solubility, required for the intended parenteral route of administration, was achieved by the presence of one or two basic amine functional groups. 相似文献
73.
Stephany Leach Mary Lewis Carolyn Chenery Gundula Müldner Hella Eckardt 《American journal of physical anthropology》2009,140(3):546-561
Previous anthropological investigations at Trentholme Drive, in Roman York identified an unusual amount of cranial variation amongst the inhabitants, with some individuals suggested as having originated from the Middle East or North Africa. The current study investigates the validity of this assessment using modern anthropological methods to assess cranial variation in two groups: The Railway and Trentholme Drive. Strontium and oxygen isotope evidence derived from the dentition of 43 of these individuals was combined with the craniometric data to provide information on possible levels of migration and the range of homelands that may be represented. The results of the craniometric analysis indicated that the majority of the York population had European origins, but that 11% of the Trentholme Drive and 12% of The Railway study samples were likely of African decent. Oxygen analysis identified four incomers, three from areas warmer than the UK and one from a cooler or more continental climate. Although based on a relatively small sample of the overall population at York, this multidisciplinary approach made it possible to identify incomers, both men and women, from across the Empire. Evidence for possible second generation migrants was also suggested. The results confirm the presence of a heterogeneous population resident in York and highlight the diversity, rather than the uniformity, of the population in Roman Britain. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc. 相似文献
74.
Annett Quiel Britta Jürgen Gundula Piechotta Anne-Pascale Le Foll Anne-Kathrin Ziebandt Christian Kohler Daniela Köster Susanne Engelmann Christian Erck Rainer Hintsche Jürgen Wehland Michael Hecker Thomas Schweder 《Applied microbiology and biotechnology》2010,85(5):1619-1627
A new approach for the detection of virulence factors of Staphylococcus aureus and Staphylococcus epidermidis using an electrical protein array chip technology is presented. The procedure is based on an enzyme-linked sandwich immunoassay, which includes recognition and binding of virulence factors by specific capture and detection antibodies. Detection of antibody-bound virulence factors is achieved by measuring the electrical current generated by redox recycling of an enzymatically released substance. The current (measured in nanoampere) corresponds to the amount of the target molecule in the analyzed sample. The electrical protein chip allows for a fast detection of Staphylococcus enterotoxin B (SEB) of S. aureus and immunodominant antigen A homologue (IsaA homologue) of S. epidermidis in different liquid matrices. The S. aureus SEB virulence factor could be detected in minimal medium, milk, and urine in a concentration of 1 ng/ml within less than 23 min. Furthermore, a simultaneous detection of SEB of S. aureus and IsaA homologue of S. epidermidis in a single assay could be demonstrated. 相似文献
75.
This study investigated the effects of cormorant colonies on plant–arthropod island food webs, the consequences of nutrient-rich
runoff on marine communities, and feedback loops from marine to terrestrial ecosystems. Terrestrial plant responses were as
expected, with the highest plant biomass on islands with low nest density and the highest nitrogen (N) content on islands
with high nest density. In contrast to our hypothesis, we found no uniform density response across guilds. Among herbivores,
the variable responses may depend on the relative importance of plant quality or quantity. As expected, nutrient-rich runoff
entered water bodies surrounding cormorant nesting islands, but only at high nest density, and increased the density of emerging
insects. This created a potential feed-back loop to spiders (major terrestrial predators), where stable isotope analyses suggested
great use of chironomids. Contrary to our expectation, this potential feed-back did not result in the highest spider density
on islands with a high cormorant nest density. Web spiders showed no changes in density on active cormorant islands, and lycosids
were actually less abundant on active cormorant islands compared to reference islands. The variable response of spiders despite
increased dipteran densities, and also in other consumer groups, may be due to direct negative effects of cormorants on soil
chemistry, vegetation cover, and other density regulating forces (for example, top–down forces) not studied here. This study
highlights the importance of including processes in the surrounding marine ecosystem to understand the impacts of seabirds
on the food web structures of their nesting islands. 相似文献
76.
Ivan Tancevski Egon Demetz Philipp Eller Kristina Duwensee Julia Hoefer Christiane Heim Ursula Stanzl Andreas Wehinger Kristina Auer Regina Karer Julia Huber Wilfried Schgoer Miranda Van Eck Jonathan Vanhoutte Catherine Fievet Frans Stellaard Mats Rudling Josef R. Patsch Andreas Ritsch 《PloS one》2010,5(1)
Background
Liver-selective thyromimetics have been reported to efficiently reduce plasma cholesterol through the hepatic induction of both, the low-density lipoprotein receptor (LDLr) and the high-density lipoprotein (HDL) receptor; the scavenger receptor class B type I (SR-BI). Here, we investigated the effect of the thyromimetic T-0681 on reverse cholesterol transport (RCT) and atherosclerosis, and studied the underlying mechanisms using different mouse models, including mice lacking LDLr, SR-BI, and apoE, as well as CETP transgenic mice.Methodology/Principal Findings
T-0681 treatment promoted bile acid production and biliary sterol secretion consistently in the majority of the studied mouse models, which was associated with a marked reduction of plasma cholesterol. Using an assay of macrophage RCT in mice, we found T-0681 to significantly increase fecal excretion of macrophage-derived neutral and acidic sterols. No positive effect on RCT was found in CETP transgenic mice, most likely due to the observed decrease in plasma CETP mass. Studies in SR-BI KO and LDLr KO mice suggested hepatic LDLr to be necessary for the action of T-0681 on lipid metabolism, as the compound did not have any influence on plasma cholesterol levels in mice lacking this receptor. Finally, prolonged treatment with T-0681 reduced the development of atherosclerosis by 60% in apoE KOs on Western type diet. In contrast, at an earlier time-point T-0681 slightly increased small fatty streak lesions, in part due to an impaired macrophage cholesterol efflux capacity, when compared to controls.Conclusions/Significance
The present results show that liver-selective thyromimetics can promote RCT and that such compounds may protect from atherosclerosis partly through induction of bile acid metabolism and biliary sterol secretion. On-going clinical trials will show whether selective thyromimetics do prevent atherosclerosis also in humans. 相似文献77.
Cell lineage specification in the nervous system 总被引:2,自引:0,他引:2
78.
The clathrin adaptor complex AP-2 serves to coordinate clathrin-coated pit assembly with the sorting of transmembrane cargo proteins at the plasmalemma. How precisely AP-2 assembly and cargo protein recognition at sites of endocytosis are regulated has remained unclear, but recent evidence implicates phosphoinositides, in particular phosphatidylinositol (4,5)-bisphosphate (PI[4,5]P2), in these processes. Here we have identified and functionally characterized a conserved binding site for PI(4,5)P2 within mu2-adaptin, the medium chain of the clathrin adaptor complex AP-2. Mutant mu2 lacking a cluster of conserved lysine residues fails to bind PI(4,5)P2 and to compete the recruitment of native clathrin/AP-2 to PI(4,5)P2-containing liposomes or to presynaptic membranes. Moreover, we show that expression of mutant mu2 inhibits receptor-mediated endocytosis in living cells. We suggest that PI(4,5)P2 binding to mu2-adaptin regulates clathrin-mediated endocytosis and thereby may contribute to structurally linking cargo recognition to coat formation. 相似文献
79.
Heusohn F Wirries G Schmidt RE Gessner JE 《Journal of immunology (Baltimore, Md. : 1950)》2002,168(6):2857-2864
The low-affinity receptor for IgG (human FcgammaRIIIA) is selectively expressed by a subset of T lymphocytes, NK cells, and macrophages. To understand the mechanisms underlying this pattern of cell type-specific expression, we initially identified alternative promoters, Pmed1/2 and Pprox, in the 5' end of the FcgammaRIIIA gene. In this study, we focused on the Pmed1 promoter and demonstrated this 93-bp region to be highly specific in governing restriction to NK/T cell lines. This property of Pmed1 is context independent and can extend to a disparate promoter. Deletion analysis defined a contribution of two separate elements located to the 5' 21-bp (-942/-922) and 3' 72-bp (-921/-850) regions of Pmed1 in conferring NK/T cell specificity. The 5' part of Pmed1 contains binding sites for Sp1 and NK element-recognizing factors and substitution mapping studies revealed a critical requirement of the Sp1-I site. The importance of Sp1 protein to regulate maximal Pmed1 promoter activity was further established by EMSAs and cotransfection experiments in Sp1-null Drosophila SL2 cells. Our data suggest that Sp1 can contribute, in part, to NK/T cell restriction and further indicate that the FcgammaRIIIA Pmed1 sequence might be useful to direct the NK/T cell-specific expression of heterologous genes. 相似文献
80.
Induction of apoptosis by telomere 3' overhang-specific DNA 总被引:3,自引:0,他引:3