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131.
François Martin Nils-Olivier Olsson Jean-François Jeannin 《Cancer immunology, immunotherapy : CII》1981,10(2-3):113-119
Summary The effects of vinblastine, colchicine, lidocaine, and cytochalasin B on tumor cell killing by BCG-activated macrophages were examined. These four drugs were selected for their action on membrane-associated cytoskeletal components, microtubules, and microfilaments. Colchicine and vinblastine, which block microtubular synthesis, inhibit macrophage-mediated tumor-cell cytotoxicity at a concentration of 10–6 M. Cytochalasin B, which disrupts microfilaments, enhances tumor cell lysis and stasis due to activated macrophages at a concentration of 10–7 M. Lidocaine, which may induce the disappearance of both microtubules and microfilaments, has the same inhibiting effect as vinblastine at a concentration of 5×10–7 M. Whereas vinblastine and lidocaine seem to act on the macrophage itself, cytochalasin B exerts its effect predominantly on the tumor cell. These results suggest that microtubules and microfilaments play a role in the destruction of tumor cells by activated macrophages. 相似文献
132.
133.
Bactericidal activity of tuftsin 总被引:2,自引:0,他引:2
Summary The biological activities of the phagocytosis stimulating tetrapeptide, Thr-Lys-Pro-Arg are discussed. A brief account on the stimulation by tuftsin of phagocytosis of various particles, including bacteria was reported. Stimulation of bactericidal activity by this tetrapeptide was investigated in vitro as well as in vivo. The potency of tuftsin to enhance blood clearing of Staphylococcus aureus, Listeria monocytogenes, Escherichia coli and Serratia marcescens by mouse peritoneal macrophages was demonstrated.Bactericidal activity and effects of tuftsin on this phenomenon were studied in liver and spleen of mice. Tuftsin stimulates these activities. Same experiments were performed in infected leukemic mice by Serratia marcescens or Escherichia coli. Results on blood clearing and bactericidal activities in liver and spleen were reported and compared to those of healthy and leukemic untreated animals. Tuftsin was found to present interesting stimulatory effects on the bactericidal activity of phagocytes. 相似文献
134.
135.
Godfried E. C. M. Strolenberg Hermy P. M. van Helden François van Herp 《Cell and tissue research》1977,180(2):203-210
Summary An ultrastructural study of the sinus gland of the crayfish Astacus
leptodactylus demonstrates that this gland is mainly composed of glial cells, axons and axon terminals. On the basis of the size, shape and electron density of the neurosecretory granules, we could distinguish five different types of axon terminals. 相似文献
136.
Résumé Les remainements intestinaux affectant la paroi intestinale sont quantifiés chez les larves d'un Amphibien Anoure,Alytes obstetricans, traitées par la thyroxine. La fraction correspondant à chaque zone composant la paroi est déterminée sur coupe. La répartition et la fréquence des noyaux marqués sont recherchées chez des larves ayant reçu de la thymidine tritiée.L'indice de marquage nucléaire de l'épithélium primaire tend vers zéro durant les 3 premiers jours du traitement. Ces résultats reflètent un ralentissement de la croissance du tissue, précédant sa dégénérescence et son élimination complète au 14ème jour d'immersion dans la solution hormonale.Dès de 3ème jour de traitement, un épithélium secondaire se développe à partir de cellules-souches basales. Son indice de marquqge croît, culmine au 9ème jour avec une valeur proche de 50%, puis s'abaisse. La prolifération cellulaire est plus modérée dans la zone extra-épithéliale, qui s'épaissit toutefois au cours de cette métamorphose provoquée.
Quantitative analysis of intestinal changes and the evolution of DNA synthesis in thyroxine-treated larvae ofAlytes obstetricans. (Amphibia, Anura)
Summary Changes in the intestinal wall ofAlytes obstetricans (Amphibia, Anura) were quantified during thyroxine treatment. The relative proportion of each intestinal wall component was determined in tissue sections. Autoradiographic studies on intestine with3H-thymidine revealed the distribution and frequency of labeled nuclei.The labeling index in the primary epithelium falls to zero by 3 days. Thyroxine treatment induces a decrease in the growth rate of this tissue, just before its degeneration and complete elimination by 14 days.Three days after T4-treatment, a secondary epithelium develops from basal stem cells. Its labeling index rises to a maximum of about 50% by 9 days, and thereafter declines. Cell proliferation is less marked in the extraepithelial zone, which nevertheless thickens during this thyroxine-induced metamorphosis.相似文献
137.
Françoise Phan-Dinh-Tuy Anne Weber Joëlle Henry Dominique Cottreau Axel Kahn 《Analytical biochemistry》1982,127(1):73-80
Electrophoresis on cellulose acetate strips was used to analyze protein kinases from normal rat liver. In addition to already well-characterized cAMP-dependent protein kinases type I and II and cAMP-independent casein kinases I and II, this method enabled the detection of several supplementary bands corresponding to kinases which were investigated according to their substrate specificity, activation by cAMP, and inhibition by the specific inhibitor of the catalytic subunit of cAMP-dependent protein kinases or by heparin. Using this rapid, sensitive, and resolutive electrophoretic method, different isozyme patterns could be obtained starting from minute amounts of different types of biological material. 相似文献
138.
Christophe Biju-Duval Hajer Ennafaa Nicole Dennebouy Monique Monnerot Françoise Mignotte Ramon C. Soriguer Amel El Gaaïed Ali El Hili Jean-Claude Mounolou 《Journal of molecular evolution》1991,33(1):92-102
Summary A characterization was conducted on mitochondrial DNA (mtDNA) molecules extracted separately from 107 European rabbits (Oryctolagus cuniculus) both wild and domestic, 13 European hares (Lepus capensis), and 1 eastern cottontail (Sylvilagus floridanus). Experimentally this study took into account restriction site polymorphism, overall length variation of the noncoding region, and numbers of repeated sequences. Nucleotide divergences indicate that the mtDNAs from the three species derived from a common ancestor some 6–8 million years (Myr) ago. Every animal appeared heteroplasmic for a set of molecules with various lengths of the noncoding region and variable numbers of repeated sequences that contribute to them. This systematic heteroplasmy, most probably generated by a rate of localized mtDNA rearrangements high enough to counterbalance the cellular segregation of rearranged molecules, is a shared derived character of leporids.The geographic distribution of mtDNA polymorphism among wild rabbit populations over the western European basin shows that two molecular lineages are represented, one in southern Spain, the second over northern Spain, France, and Tunisia. These two lineages derived from a common ancestor some 2 Myr ago. Their present geographical distribution may be correlated to the separation of rabbits into two stocks at the time of Mindel glaciation.Finally the distribution of mtDNA diversity exhibits a mosaic pattern both at inter- and intrapopulation levels. 相似文献
139.
Stephen Phillips Matt Cotten Françoise Laengle-Rouault Gotthold Schaffner Max L. Birnstiel 《Chromosoma》1992,101(9):549-556
The sphere organelles (spheres) ofXenopus and other amphibian oocytes are known to contain small nuclear ribonucleoprotein particles (snRNPs) and have been suggested to play a role in snRNP complex assembly. Coupled with the similarities that exist between spheres and nucleoli and the quantitative and kinetic aspects of snRNA synthesis in theXenopus oocyte, we have investigated whether or not the U snRNA encoding genes are amplified inXenopus oogenesis, the spheres being possible sites for the location of such extrachromosomal gene copies. By applying a number of quantitative nucleic acid hybridization procedures to both total and fractionated oocyte and somatic DNA, employing both homologous and heterologous U snRNA gene probes and suitable amplification and non-amplification control probes, we show that the U snRNA genes do not undergo any major amplification inXenopus oogenesis. Therefore, the analogy between the sphere organelles and nucleoli appears to be limited. The role of the spheres and their relationship to other snRNP containing structures, specifically B snurposomes, and the sphere organizer loci remains obscure.by A. Spradling 相似文献
140.
Bonaventura Ruiz-Montasell F. Javier Casado Antonio Felipe Marçal Pastor-Anglada 《The Journal of membrane biology》1992,128(3):227-233
Summary The characteristics of uridine transport were studied in basolateral plasma membrane vesicles isolated from rat liver. Uridine was not metabolized under transport measurement conditions and was taken up into an osmotically active space with no significant binding of uridine to the membrane vesicles. Uridine uptake was sodium dependent, showing no significant stimulation by other monovalent cations. Kinetic analysis of the sodium-dependent component showed a single system with Michaelis-Menten kinetics. Parameter values were K
M 8.9
m and V
max 0.57 pmol/mg prot/sec. Uridine transport proved to be electrogenic, since, firstly, the Hill plot of the kinetic data suggested a 1 uridine: 1 Na+ stoichiometry, secondly, valinomycin enhanced basal uridine uptake rates and, thirdly, the permeant nature of the Na+ counterions determined uridine transport rates (SCN– > NO
3
–
> Cl– > SO
4
2–
). Other purines and pyrimidines cis-inhibited and trans-stimulated uridine uptake.This work has been partially supported by grant PM90-0162 from D.G.I.C.Y.T. (Ministerio de Educación y Ciencia, Spain). B.R.-M. is a research fellow supported by the Nestlé Nutrition Research Grant Programme. 相似文献