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921.
Zusammenfassung 541 Serumproben von nichtverwandten Deutschen aus dem Kölner Raum wurden auf ihre Pt- und C3-Typen untersucht. Bei 537 Seren fand sich eine Überein-stimmung der Pt A-Typen mit den C3 F-Typen, der Pt AB-Typen mit den C3 FS-Typen und der Pt B-Typen mit C3 S-Typen. Die C3-Varianten F0.65S, F0.6S, F0.5S wurden als Pt AB bestimmt, die C3-Variante F0.55S wurde als Pt B bestimmt. Die Frage der Vergleichbarkeit der Systeme sowie die Untersuchungsmethoden werden diskutiert.
Comparative studies on posttransferrin (Pt) and C3 in the polymorphism of the third component of human complement
Summary Sera of 541 unrelated Germans from the Cologne area were examined for their Pt and C3 types. There was correspondence between Pt A and C3 F, Pt AB and C3 FS, and Pt B and C3 S in 537 sera. C3 variants F0.65S, F0.6S, F0.5S were determined as Pt AB, C3 F0.55S was determined as Pt B. The question of possible identity and the methods used are discussed.相似文献
922.
Dimitrios G. Oreopoulos Sandra Pitel Harry Husdan George A. de Veber Abraham Rapoport 《CMAJ》1974,110(1):43-47
Our findings support the earlier observation of Yendt, Connor and Howard that uremic serum inhibits the calcification of rachitic rat cartilage in vitro. We also confirmed their studies showing that this inhibition is not the consequence of increased levels of serum magnesium or blood urea. In addition, we have shown that aqueous solutions of creatinine and uric acid in concentrations up to 20 mg./100 ml. do not cause any inhibition.Hemodialysis of uremic patients does not change the inhibitory activity of their blood. In contrast, after 24 hours of peritoneal dialysis, the blood of most patients does not inhibit calcification.The inhibitory activity of uremic serum, observed in vitro, may be important in the pathogenesis of osteomalacia in patients with renal failure. Failure of hemodialysis to alter this activity may contribute to the progression of renal osteodystrophy in patients on maintenance hemodialysis. 相似文献
923.
Summary
Selaginella pilijera consistently displays two rows of microsporangia and two rows of megasporangia. It is therefore possible to detect in longitudinal sections of strobili at least three significant differences in development between both types of sporangia prior to meiosis: size of young sporangia, abortion or development of sporocytes based an RNA staining, and presence or absence of callose walls around sporocytes. The functional significance of these differences is discussed in relation to the heterosporous habit and higher plant sporogenesis. 相似文献
924.
Reversion to the Streptococcal State of Enterococcal Protoplasts, Spheroplasts, and L-Forms 总被引:8,自引:6,他引:2
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A method is described for predetermining whether lysozyme-damaged enterococci grow as either the parent strain or as L-forms. Organisms treated with lysozyme grew as L-forms on media solidified with low concentrations of agar, or the damaged cells grew as streptococci on media solidified with high concentrations of gelatin. After induction, some of the L-forms reverted to the parent strain, but most did not during three routine subcultures. Continued spontaneous reversion occurred through approximately 30 subcultures after induction. However, subsequent progeny did not revert, even when subjected to conditions such as the gelatin medium which strongly favors growth in the streptococcal phase. 相似文献
925.
Using appropriate precursors, the two unnatural alkaloids 4(5)-[N-isocaproylaminomethyl]imidazole and 3-[2-N-isovalerylaminoethyl]pyrazole were produced by Dolichothele sphaerica. The former compound represents an unnatural alkaloid formed by the simultaneous introduction of two unnatural precursors, namely isocaproic acid and 4(5)-aminomethylimidazole. The latter compound represents an aberrant alkaloid formed by the introduction of a precursor of different heterocyclic entity, 3-aminoethylpyrazole. 相似文献
926.
Genetics and Biochemistry of Pyrimidine Biosynthesis in Bacillus subtilis: Linkage Between Mutations Resulting in a Requirement for Uracil 总被引:1,自引:1,他引:0
A number of independently derived uracil-requiring mutant strains of the parent strain 168 were mapped by inter-mutant transformation crosses. Only a few of these mutant strains were found to be transformable. Studies were performed in which these transformable uracil-requiring mutant strains were used as the recipient of deoxyribonucleic acid extracted from phenotypically similar mutant strains. The results yielded data resulting in a fine-structure map in which all mutations were found to be linked in a small region corresponding to that previously published as the uracil region of the Bacillus subtilis genome. 相似文献
927.
Harry G. Rittenhouse J. Barry Rodda Bruce A. McFadden 《Journal of bacteriology》1973,113(3):1400-1403
Antibodies to a protein present in the cell envelope of Hydrogenomonas facilis agglutinate many gram-negative bacteria and a few gram-positive bacteria. Immunodiffusion studies of extracts from the various organisms tested indicate the presence of components sharing antigenic determinants with the cell envelope protein in all bacteria which can be agglutinated and a few that cannot. Cross-reacting components were not detected in extracts of Mycoplasma laidlawii, Anacystis nidulans, and several eukaryotic organisms. 相似文献
928.
Isolation of Assimilatory- and Dissimilatory-Type Sulfite Reductases from Desulfovibrio vulgaris
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Bisulfite reductase (desulfoviridin) and an assimilatory sulfite reductase have been purified from extracts of Desulfovibrio vulgaris. The bisulfite reductase has absorption maxima at 628, 580, 408, 390, and 279 nm, and a molecular weight of 226,000 by sedimentation equilibrium, and was judged to be free of other proteins by disk electrophoresis and ultracentrifugation. On gels, purified bisulfite reductase exhibited two green bands which coincided with activity and protein. The enzyme appears to be a tetramer but was shown to have two different types of subunits having molecular weights of 42,000 and 50,000. The chromophore did not form an alkaline ferrohemochromogen, was not reduced with dithionite or borohydride, and did not form a spectrally visible complex with CO. The assimilatory sulfite reductase has absorption maxima at 590, 545, 405 and 275 nm and a molecular weight of 26,800, and appears to consist of a single polypeptide chain as it is not dissociated into subunits by sodium dodecyl sulfate. By disk electrophoresis, purified sulfite reductase exhibited a single greenish-brown band which coincided with activity and protein. The sole product of the reduction was sulfide, and the chromophore was reduced by borohydride in the presence of sulfite. Carbon monoxide reacted with the reduced chromophore but it did not form a typical pyridine ferrohemochromogen. Thiosulfate, trithionate, and tetrathionate were not reduced by either enzyme preparation. In the presence of 8 M urea, the spectrum of bisulfite reductase resembles that of the sulfite reductase, thus suggesting a chemical relationship between the two chromophores. 相似文献
929.
930.
Summary The first morphological examination of the surface and internal anatomy of the kinorhynch, Echinoderes dujardini was undertaken using the scanning and transmission electron microscopes.The oral styles and at least the first ring of scalids were found to have a basal pectinate fringe that resembles the pectinate fringe found at the posterior margins of the trunk segments. In addition to the fringe, the scalids were subdivisible into at least two distinct classes which are similar in structure to the trichoscalid and type I spinocalid identified by Moritz and Storch in T. giganteus. The trichoscalid of E. dujardini however, was found to possess a unique fluted cuticle structure with spines arising only on the medial surface.Although pores are known to occur in the cuticle of homalorhagid kinorhynchs, such pores were not found in the cyclorhagid, E. dujardini.A structure, provisionally designated sensory-like structure is described. Some 60 or more compactly placed spines occur as paired circles or ellipses on all but the terminal trunk segment.An electron dense structure was seen in the subsurface of the placids that may lend mechanical support and may contribute to the Napoleon hats seen with light microscopy. Micrographs of the circumentric nerve ring, gut, epidermis and pharynx are presented. Located at the anterior of the pharynx is a peripharyngeal muscle. The muscle, composed of two membrane bounded smooth muscle strands, probably acts as a sphincter to prevent a reverse flow of food material. Finally, scanning micrographs show a single opening located dorsolaterally on the 10th segment. This opening has been interpreted as an excretory pore even though it does not occur ventrolaterally on the 11th segment as reported for other kinorhynchs.This investigation was supported in part by NIH Contract 70-4136 from the Division of Research Resources. 相似文献