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Molecular genetic diagnosis of sickle cell disease using dried blood specimens on blotters used for newborn screening 总被引:12,自引:1,他引:11
David C. Jinks Mikeanne Minter Deborah A. Tarver Mindy Vanderford J. Fielding Hejtmancik Edward R. B. McCabe 《Human genetics》1989,81(4):363-366
Summary The protein-based technologies used to screen newborns for sickle cell disease require confirmation with a liquid blood specimen.
We have developed a strategy for rapid and specific genotypic diagnosis using DNA extracted from a dried blood spot on the
filter paper blotter used to screen newborns. DNA could be microextracted from a specimen as small as a 1/8 inch diameter
punched disc representing the dried equivalent of approximately 3 μl of whole blood. We utilized the DNA from a 1/4 inch diameter
specimen (12 μl equivalent) for polymerase chain reaction amplification of the β-globin region spanning the sickle cell mutation
with detection by allele-specific oligonucleotide probes. Molecular confirmation of genotype from the original blotter would
reduce the personnel costs associated with obtaining follow-up liquid blood specimens and would provide information to the
family in a more timely and less equivocal manner. 相似文献
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A Yasui A J Douglas B Walker D F Magee R F Murphy 《International journal of peptide and protein research》1990,35(4):301-305
The C-terminal tetrapeptide, Trp-Met-Asp-Phe-NH2, is a full agonist of gastrin, but des-Phe analogues, including Boc-Trp-Met-Asp-NH2, are antagonists. To ascertain the minimum structural requirement for an antagonist, we used conventional solution phase methodology to synthesize analogues with further modifications including removal of the alpha-amino group of Trp, conversion of the indole to a phenyl ring, and methylation of amide bonds. These analogues were tested for their effect on pentagastrin-stimulated acid release in dogs surgically prepared with a gastric fistula. When infused intravenously at a dose of 20 pmol kg-1 h-1, the peptides significantly inhibited acid secretion. The extent of inhibition ranged from 12% to 60%. Thus, tripeptide analogues based on the C-terminal sequence of gastrin act as potent and specific antagonists of gastrin-stimulated acid secretion. 相似文献
108.
Whether female crickets choose among males based on characteristics of the courtship song is uncertain, but in many species,
males not producing courtship song do not mate. In the house cricket,Acheta domesticus, we examined whether a female chose or rejected a male based on his size, latency to chirp, latency to produce courtship
song, or rate of the high-frequency pulse of courtship song (“court rate”). We confirmed that females mated only with males
that produced courtship song, but we found no evidence that the other factors we measured affected a female’s decision to
mate. In addition, we investigated whether the outcome of male agonistic encounters affected the subsequent production of
courtship song. In one experiment, we observed courtship and mating behavior when a single female was placed with a pair of
males following a 10-min interaction period between the two males. Winners of male agonistic encounters had higher mating
success. However, winners and losers of agonistic encounters were not different in their likelihood or latency to produce
courtship song or in the number of times they were disrupted by the other male in the pair. In a second experiment, we allowed
two males to interact for a 10-min period, but following this interaction period, we placed a female with each male separately
and observed courtship and mating behavior. The mating success of winners and losers was not different under these circumstances,
and we found no differences between winners and losers in any subsequent courtship or mating behavior examined. We conclude
that winning agonistic encounters influences a male’s mating success in ways other than his production of courtship song and
this effect is lost when winning and losing males are separated and each is given an opportunity to mate. 相似文献
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THE INTERACTION OF CATIONIC LIPOSOMES CONTAINING ENTRAPPED HORSERADISH PEROXIDASE WITH CELLS IN CULTURE 总被引:8,自引:6,他引:2
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Wayne E. Magee Charles W. Goff Jean Schoknecht M. Diane Smith K. Cherian 《The Journal of cell biology》1974,63(2):492-504
Cationic liposomes composed of sphingomyelin, cholesterol, and stearylamine were prepared with horseradish peroxidase trapped inside. Stable particles were formed in which 10–12% of the enzymic activity appeared to be located at, or near, the outer surface of the liposome. Adsorption and uptake of liposomes by HeLa cells were followed cytochemically by electron microscopy and quantitated by enzyme assay and by the distribution and fate of particles labeled with [14C]cholesterol and [125I]horseradish peroxidase. The particles were adsorbed by HeLa cells at least 300 times as efficiently as was free horseradish peroxidase. Many of the particles remained at the cell surface, but numerous membrane-bound cytoplasmic inclusions were observed to contain peroxidase-staining material. In addition, many areas of the cell membrane gave a positive staining reaction. It was concluded that many particles (presumably the larger ones) did not gain access to the interior of the cells, many were phagocytized, and some enzyme was transferred to the cell membrane, perhaps as a result of fusion of the liposomal membrane with the cell membrane. 相似文献