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971.
972.
José Manuel Fernández-Ábalos Helen Fox Chris Pitt Brian Wells & John H. Doonan 《Molecular microbiology》1998,27(1):121-130
Green fluorescent protein (GFP) is a useful reporter to follow the in vivo behaviour of proteins, but the wild-type gfp gene does not function in many organisms, including many plants and filamentous fungi. We show that codon-modified forms of gfp , produced for use in plants, function effectively in Aspergillus nidulans both as gene expression reporters and as vital reporters for protein location. To demonstrate the use of these modified gfp s as reporter genes we have used fluorescence to follow ethanol-induced GFP expression from the alcA promoter. Translational fusions with the modified gfp were used to follow protein location in living cells; plant ER-retention signals targeted GFP to the endoplasmic reticulum, whereas fusion to the GAL4 DNA-binding domain targeted it to the nucleus. Nuclear-targeted GFP allowed real-time observation of nuclear movement and division. These modified gfp genes should provide useful markers to follow gene expression, organelle behaviour and protein trafficking in real time. 相似文献
973.
Katherine ES Lindhe Danny S Meldgaard Per M Jensen Geoffrey A Houser Mette Berendt 《Acta veterinaria Scandinavica》2009,51(1):56
Background
Large regions of central and eastern Europe are recognized as areas where tick-borne encephalitis virus (TBEV) is endemic, including countries neighbouring Denmark. It is therefore timely and relevant to determine if TBEV infections occur in Denmark. This study investigates the presence of antibodies against TBEV in a cross-section of the Danish canine population to assess the level of exposure to TBEV and possibly identify TBEV microfoci in Denmark. 相似文献974.
975.
Characterization of a membrane surface glycoprotein associated with T-cell activation 总被引:4,自引:0,他引:4
J R Sportsman M M Park D A Cheresh M Fukuda J H Elder R I Fox 《Journal of immunology (Baltimore, Md. : 1950)》1985,135(1):158-164
A cell surface antigen (gp140) was previously shown to exist on T cell subsets as well as on monocytes and macrophages in normal peripheral blood. Elevated expression of this antigen was associated with immune system disorders, acute lymphocytic leukemias, and in vitro activation of T cells. The antigen could be identified with monoclonal antibody (MAb) T305. Gp140 was a biosynthetic product of T cells because it could be labeled with [3H]leucine or [3H] glucosamine. Biochemical studies of gp140 used high performance liquid chromatography with nitrocellulose blotting to isolate aliquots suitable for 125I radiolabeling and immunoprecipitation to demonstrate: a) a reduction in m.w. of gp140 KD to 90 KD after deglycosylation by trifluoromethanesulfonic acid, b) alteration of isoelectric point from 4.1 to 5.7 after neuraminidase treatments, c) absence of N-linked sugars based on resistance to endoglycosidase F, d) resistance to trypsin and chymotrypsin digestion but susceptibility to pronase, and e) presence of sialic acid and lactosaminoglycan as O-linked sugars. Gp140 could be labeled with the periodate/NaB[3H]4 technique, indicating its similarity to a class of sialoglycoproteins previously described on activated T-cells in mouse and man. The antigenic epitope recognized by MAb T305 contains sialic acid linked (2----3) to galactose; however, periodate oxidation of the exocyclic ring of sialic acid did not affect binding by MAb T305. In an attempt to determine the functional role of gp140, we tested the ability of MAb T305 to block: a) proliferation of peripheral blood lymphocytes to mitogens, b) response to interleukin 2 (IL 2) of an IL 2 dependent T cell line, and c) growth of a T-ALL derived cell line. No inhibition of proliferation or growth was noted. Although the function of gp140 remains unknown, its association with lymphocyte activation and certain disease states suggests that it may provide a target for modulation of the immune response. These studies characterize the structural features of gp140 and further define the epitope recognized by MAb T305. 相似文献
976.
Richard A. Fox 《American anthropologist》1999,101(4):853-854
Archaeology on the Great Plains. W. Raymond Wood. ed. Lawrence: University Press of Kansas, 1998. 522 pp. 相似文献
977.
The effects of simulated goose grazing on common saltmarsh-grass Puccinellia maritima plants were tested on a Danish salt marsh during the flightless moulting period of greylag geese Anser anser (3–21 June 1998). Plants in an area exclosed from the influence of grazing and the nutrient effects of goose faeces were subject to removal of youngest lamina at 3-, 6-, 9- and 18-day intervals during this period. Average biomass and protein accumulation between harvests was highest at defoliation intervals of 9 days or more. Field observations from two separate study areas demonstrated geese returned to regraze the Puccinellia sward after 6–8 days and oesophageal contents from feeding geese showed selection for lamina lengths consistent with the results of clipping every 6 days. Geese therefore regrazed Puccinellia patches at shorter intervals than expected were they to maximise their intake of biomass or protein at each visit. However, total cumulative lamina elongation, equivalent to the long term gain during the entire moult period, showed no significant difference between the three most intensive defoliation treatments, which were significantly greater than those of plants defoliated at 18 day intervals. Highest overall lamina protein levels were maintained at 6- and 9-day defoliation intervals. This suggests geese regrazed Puccinellia patches at a rate that maximised their number of harvests during the flightless period, but maintained highest protein levels and overall biomass in the sward. This suggests, in line with earlier studies, that moulting greylag geese combine dietary selection, reduced nitrogen excretion and regrazing patterns to meet protein demands during regrowth of flight feathers. 相似文献
978.
Boyd B Scott Paola F Zaratin Geoffrey D Clarke Michael R Barnes Paul R Murdock Frank J Lynch Malcolm Duckworth 《DNA sequence》2004,15(1):1-8
Murine NGD5 is a gene identified from NG108-15 cells which is postulated to be involved in opioid receptor function. Here we report the cloning and characterization of a cDNA C20orf9-003 (ACI-1) encoding the human orthologue of the mouse NGD5. Analysis of the genomic structure revealed that C20orf9-003 (ACI-1) contains 13 exons and 12 introns, spanning 52.5kb of genomic DNA and is a variant of C20orf9. Chromosomal localization of human C20orf9-003 (ACI-1) assigned this gene to chromosome 20q13.12. Genes at this locus have been associated with the progression and possibly the development of various cancers. In addition several linkage studies support the possibility that one or more genes affecting obesity are located in 20q13. No function can be clearly assigned to C20orf9-003 (ACI-1), however, the protein has a cytoplasmic subcellular location and the secondary structure contains a Rossman fold like feature which is found in many nucleotide binding proteins. 相似文献
979.
980.
β-Alanyl-, acetimidoyl-, and carbamoyl-bradykinin [(IV), (V), and (VI), respectively] have been synthesized by the picolyl ester method. The first two analogs have very low smooth muscle contracting activity, but the carbamoyl derivative is as fully active as bradykinin itself. 相似文献