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1.
《Bioorganic & medicinal chemistry letters》2014,24(13):2949-2953
The G protein-coupled receptor 40 (GPR40) mediates enhancement of glucose-stimulated insulin secretion in pancreatic β cells. The GPR40 agonist has been attracting attention as a novel insulin secretagogue with glucose dependency for the treatment of type 2 diabetes. The optimization study of compound 1 led to a potent and bioavailable GPR40 agonist 24, which showed insulin secretion and glucose lowering effects in rat OGTT. Compound 24 is a potential lead compound for a novel insulin secretagogue with a low risk of hypoglycemia. 相似文献
2.
Summary Different mushrooms, mosses and corresponding soil samples have been collected mainly from two sites in the alpine region of southwestern Bavaria. At the end of the growthseason, September 1986, gamma spectroscopic analysis showed that the moss-, mould, and needle-layer contained considerably more 134Cs and 137Cs activity per unit fresh weight than eight different species of mushroom. These two isotopes were carried into the biotop mainly as a consequence of the Chernobyl accident. 131J could not be found any more in the samples ca. 5–6 months after the catastrophe. The activity of the cesium isotopes decreased with increasing soil depth. In the mushrooms the activity was relatively high in Xerocomus badius and surprisingly low in Boletus edulis; samples of the latter and of Cantharellus cibarius collected in September 1985 (before the accident) and kept deep frozen contained almost identical amounts of 137Cs as those collected from August to October 1986. Mushrooms contained considerably more of the natural isotope 40K than the needlelayers and the soil samples in the neighbourhood. In all mushrooms except Xerocomus badius the activity of 40K was generally higher than the 137Cs activity. The results indicate that except Xerocomus badius the analyzed mushrooms do not actively take up Cs from the soil, in contrast to K. 相似文献
3.
Peter Alliger Wolfgang Traut Eric Carstens Ellen Fanning 《Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression》1988,951(2-3)
A monkey cell factor that interacts specifically with double- and single-stranded DNA sequences in the early domain of the simian virus 40 (SV40) core origin of replication was identified using gel-retention assays. The protein was enriched over 1200-fold using ion-exchange and affinity chromatography on single-strand DNA cellulose. Binding of protein to mutant origin DNA restriction fragments was correlated with replication activity of the mutant DNAs. Exonuclease footprint experiments on single-stranded DNA revealed prominent pause sites in the early domain of the core origin. The results suggest that this cellular protein may be involved in SV40 DNA replication. 相似文献
4.
5.
Peter Zahradka 《Molecular and cellular biochemistry》1992,110(1):65-73
Summary The role of DNA polymerases in the replication of SV40 DNA was studied using a T-antigen-dependent assay supplemented with
a human KB cell extract. Inhibition of DNA polymerase α by addition of aphidicolin or monoclonal antibodies prevented DNA
synthesis, confirming the requirement for this enzyme in replication. The replication process was unaffected by ddTTP at a
concentration (5 μM) inhibitory to DNA polymerases β and γ, however, higher concentrations of ddTTP (200 μM) caused an apparent
accumulation of relaxed circular plasmid with a concomitant decrease in DNA synthesis. An analysis of this replication intermediate
indicated that it was formed during the replication reaction and that the replicative cycle was nearly complete. A kinetic
study of ddTTP inhibition strongly suggested DNA polymerase ε (PCNA-independent DNA polymerase δ) was the target of the inhibitor
and that this enzyme functions during the final stages of DNA replication. 相似文献
6.
Raymond L. Mernaugh Michael H. Shearer Robert K. Bright Robert E. Lanford Ronald C. Kennedy 《Cancer immunology, immunotherapy : CII》1992,35(2):113-118
Summary Baculovirus-derived recombinant simian virus 40 (SV40) large tumor antigen (SV40 T-Ag), a monoclonal antibody specific for SV40 T-Ag (Ab-1 preparation), and a monoclonal anti-idiotypic antibody (anti-Id), designated 58D, were used to analyze the humoral immune response of Balb/c mice either immunized with recombinant SV40 T-Ag or challenged with SV40-transformed cells. Inhibition assays indicated that antibodies from mice immunized with SV40 T-Ag and from those bearing SV40 tumor inhibited the SV40 T-Ag/Ab-1 reaction. These data suggested that the antibody response in immunized or tumorchallenged mice recognized similar epitope(s) on SV40 T-Ag to that detected by the monoclonal Ab-1. These anti-(SV40 T-Ag) response antibodies also inhibited the Ab-1/anti-Id reaction and recognized the anti-Id in direct binding assays. Together, these data indicate that murine anti-(SV40 T-Ag) responses shared an idiotope with a monoclonal anti-(SV40 T-Ag) Ab-1 preparation. This idiotope, which is recognized by the monoclonal anti-Id preparation, 58D, appears to be involved in the humoral immune response to SV40 T-Ag in both SV40-T-Ag-immunized and tumor-bearing mice. The monoclonal anti-Id preparation may represent a focal point for manipulating the humoral immune response to tumors induced by SV40-transformed cells. 相似文献
7.
Targeting of T7 RNA polymerase to tobacco nuclei mediated by an SV40 nuclear location signal 总被引:9,自引:0,他引:9
Michael W. Lassner Aubrey Jones Steve Daubert Luca Comai 《Plant molecular biology》1991,17(2):229-234
We have expressed two T7 RNA polymerase genes by electroporation into tobacco protoplasts. One of the genes was modified by inserting nucleotides encoding a viral nuclear localization signal (NLS) from the large T antigen of SV40. Both T7 RNA polymerase genes directed synthesis of a ca. 100 kDa protein in the electroporated protoplasts. T7 RNA polymerase activity was detected in extracts of protoplasts electroporated with both genes. Immunofluorescence analysis of these protoplasts indicated that only the polymerase carrying the NLS accumulated in the cell nucleus. These experiments suggest that mechanisms involved in the transport from the cytoplasm to the nucleus are similar in plant and animal cells. This system demonstrates the feasibility of T7 RNA polymerase-based approaches for the high-level expression of introduced genes in plant cells. 相似文献
8.
B Schwartz P Vicart C Delouis D Paulin 《Biology of the cell / under the auspices of the European Cell Biology Organization》1991,73(1):7-14
The aim of this study was to investigate a new method to enhance the efficiency to create mammalian cell lines. Cell immortalization was achieved by intranuclear microinjection of a recombinant DNA construct composed of a constitutive promoter controlling the genes encoding immortalizing proteins; the sequences coding for the large T and small t antigens were fused downstream of regulatory elements from the vimentin gene, the activation of which characterizes the vast majority of cells growing in vitro. Data show that the efficiency of the immortalizing procedures using the SV40 early genes could be enhanced by the control elements derived from the human vimentin (HuVim) 5' sequences that contained nucleotides -878 to +93 from the CAP site. This HuVim 830-T/t recombinant was used to create cell lines from numerous primary cultures of different origins: rabbit, porcine and human endothelial cells, rabbit and bovine epithelial cells. A set of large T-expressing cells was derived, and these cells retained characteristics of differential cells: binding of Ulex europaeus lectin and synthesis of Factor VIII for human endothelial cells; network of cytokeratin for bovine oviductal cells and rabbit mammary cells. 相似文献
9.
Restriction endonuclease EcoO109 from Escherichia coli H709c with heptanucleotide recognition site 5'-PuG/GNCCPy 总被引:1,自引:0,他引:1
A new restriction endonuclease, EcoO109, has been isolated from Escherichia coli H709c by polyethyleneimine (PEI) precipitation, DEAE-cellulose chromatography and heparin agarose chromatography. The yield was high, more than 3000 units/g of wet cells. The EcoO109 endonuclease recognizes and cleaves a nucleotide sequence of (formula: see text), in the presence of 10 mM Mg2+. The enzyme will be useful for structural analysis and molecular cloning of DNA because of the stability, high yield and easy handling of the producer strain. 相似文献
10.
John M. Lehman Emilee Dickerson Thomas Friedrich Judith Laffin 《In vitro cellular & developmental biology. Animal》1995,31(10):806-810
Summary The changes in cell size and total protein were determined for G1-arrested, contact-inhibited CV-1 cells infected with Simian
virus 40 (SV40). The assays used were the Biorad total protein assays (Bradford and DC protein assays) on a standard number
of cells, total protein as assayed by fluorescein isothiocyanate (FITC) and SR101 by flow cytometry, orthoganol (90°) light
scatter by flow cytometry, and direct microscopic measurement with an ocular micrometer. Uninfected CV-1 cells and two cell
lines with variations in DNA content (diploid vs. tetraploid) were used as controls for the studies presented. The results
demonstrated a 40–60% increase in total protein at 32 to 42 h postinfection. These increases were similar to values obtained
as control cells progress through the cell cycle. At later times postinfection (>42 h), total protein decreased due to cellular
changes resulting from viral replication and cell death. 相似文献