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1.
Identification of an outer mitochondrial membrane protein that interacts with a synthetic signal peptide 总被引:5,自引:0,他引:5
L L Gillespie 《The Journal of biological chemistry》1987,262(17):7939-7942
Chemical cross-linking procedures have been employed to study possible interactions between components of the mitochondrial outer membrane and NH2-terminal signal sequences located in proteins destined for import into the organelle. A synthetic peptide comprising amino acids 1-27 of pre-ornithine carbamyltransferase (pOCT) was found to interact specifically with a mitochondrial polypeptide of apparent molecular size 30 kDa. Membrane fractionation and protease accessibility analyses indicated that the polypeptide, designated p30, is located in the outer membrane. Binding of the synthetic peptide to p30 was saturable and reversible; Scatchard analysis of the binding data revealed a dissociation constant of 2 X 10(-6) M and predicts that p30 constitutes 4-10% of the outer mitochondrial membrane protein. Mild trypsin digestion of the mitochondrial surface destroyed both the ability of p30 to cross-link to the signal peptide and the ability of the organelle to import pOCT. Neither parameter was affected, however, by pretreatment of mitochondria with 1 M KCl. 相似文献
2.
A total of 101 sows was used to examine postpartum progesterone levels and litter performance following administration of 15 mg prostaglandins F(2alpha) (PGF(2alpha) n = 48) given within 12 h after farrowing. Daily blood samples and rectal temperatures were taken from all sows during the first 3 d post partum. Plasma progesterone (P(4)) concentrations were determined by radioimmunoassay (RIA). Regardless of treatment, plasma P(4) levels for all sows decreased in a similar fashion over the 3 d sampled. Mean (+/- SEM) P(4) on Day 2 (0.55 +/- 0.06 ng/ml) and Day 3 (0.38 +/- 0.04 ng/ml) were lower (P<0.01) than on Day 1 (0.98 +/- 0.08 ng/ml). Rectal temperature did not differ between PGF(2alpha) treated and nontreated sows nor was it different over the days measured. Litter characteristics, including survival rates on Day 7 and at weaning, and body weight on Days 3 and 35, were not affected by treatment. It was concluded that PGF(2alpha) administration to sows within 12 h post farrowing had no affect on the rate of luteal regression, as determined by P(4) concentration, nor on subsequent litter performance. 相似文献
3.
Structural relationships among chloramphenicol-resistance plasmids of Staphylococcus aureus 总被引:2,自引:0,他引:2
Abstract Twelve different chloramphenicol-resistance (Cmr ) plasmids detected in Staphylococcus aureus strains isolated between 1952 and 1981 were characterized by restriction endonuclease, DNA hybridization and heteroduplex analyses. These studies revealed three families of Cmr plasmids which were distinguished by their chloramphenicol acetyltransferase sequences; the prototype plasmids of the families were pC221, pC223 and pC194. The cat and replication ( rep ) genes of the plasmid pC221 were highly conserved in other pC221 family members and were related to their homologs in the pC223 family plasmids; however, the cat and rep genes of the pC194 family plasmids were distinct. 相似文献
4.
Growth of Mycobacterium phlei under low oxygen tension resulted in specific activities two to twenty times lower for formate dehydrogenase, malate dehydrogenase, beta-hydroxybutyrate dehydrogenase, lactate oxidase and NADH dehydrogenase than when cultures were grown under high aeration. An increase in fumarate reductase and succinate dehydrogenase occurred with M. phlei grown under low oxygen tension. Malate: vitamin K dehydrogenase and glucose-6-phosphate dehydrogenase activity were not significantly affected by the oxygen tension used to grow the bacteria, and neither culture contained a lactate dehydrogenase. With growth of M. phlei in conditions of low oxygen tension, cytochrome a was not detected, but cytochrome b was prominent in membranes and cytochrome c was present in the soluble fraction. 相似文献
5.
The gene for autosomal dominant polycystic kidney disease lies in a 750-kb CpG-rich region. 总被引:17,自引:0,他引:17
G G Germino D Weinstat-Saslow H Himmelbauer G A Gillespie S Somlo B Wirth N Barton K L Harris A M Frischauf S T Reeders 《Genomics》1992,13(1):144-151
PKD1, the locus most commonly affected by mutations that produce autosomal dominant polycystic kidney disease (ADPKD), has previously been localized to chromosome 16p13.3. Since no cytogenetic abnormalities have been found in association with ADPKD, flanking genetic markers have been required to define an interval--the PKD1 region--that contains the PKD1 gene. In this report we demonstrate, through the construction of a long-range restriction map that links the flanking genetic markers GGG1 (D16S84) and 26.6PROX (D16S125), that the PKD1 gene lies within an extremely CpG-rich 750-kb segment of chromosome 16p13.3. Approximately 90% of this region has been cloned in three extensive cosmid/bacteriophage contigs. The cloned DNA is a valuable resource for identifying new closer flanking genetic markers and for isolating candidate genes from the region. 相似文献
6.
G H Thorpe L J Kricka E Gillespie S Moseley R Amess N Baggett T P Whitehead 《Analytical biochemistry》1985,145(1):96-100
6-Hydroxybenzothiazole, 2-cyano-6-hydroxybenzothiazole, and 2-(6-hydroxy-2-benzothiazolyl)thiazole-4-carboxylic acid (dehydroluciferin) dramatically enhance light emission from the horseradish peroxidase conjugate catalyzed oxidation of luminol, isoluminol, N-(6-aminobutyl)-N-ethyl isoluminol, and 7-dimethylaminonaphthalene-1,2-dicarboxylic acid hydrazide by either peroxide or perborate. Light emission is enhanced by up to 1000-fold, which is an improvement over the enhancement previously observed using firefly luciferin (4,5-dihydro-2-(6-hydroxy-2-benzothiazolyl)thiazole-4-carboxylic acid). Enhancement is influenced by enhancer concentration and pH. Spectral scans of light emitted in enhanced and unenhanced reactions are similar, suggesting that aminophthalate products, and not the enhancers, are the emitters. 相似文献
7.
8.
A mutant of E. coli, T
s68b, selected as unable to grow at 43 C, is unable to synthesize proteins at 43 C, though it can carry out this function at 30 C. This defect is shown to be in the protein-synthetic rather than the RNA-synthetic machinery by an analysis of the response of the strain to infection with the RNA bacteriophage f2. An analysis of the capacity for RNA synthesis and the polyribosome content of these cells at 44 C indicates that the defect resides in the elongation step of protein synthesis. No defects could be detected in vitro. The results are discussed in light of similar data on other mutants and in relation to the general approach of analyzing complex mutants selected with ill-defined phenotypes.This work was supported by Grant GM14368 from the National Institute of Health. 相似文献
9.
10.