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191.
AAM Coelho-Castelo AP Trombone RS Rosada RR Santos Jr VLD Bonato A Sartori CL Silva 《Genetic vaccines and therapy》2006,4(1):1-10
In order to assess a new strategy of DNA vaccine for a more complete understanding of its action in immune response, it is important to determine the in vivo biodistribution fate and antigen expression. In previous studies, our group focused on the prophylactic and therapeutic use of a plasmid DNA encoding the Mycobacterium leprae 65-kDa heat shock protein (Hsp65) and achieved an efficient immune response induction as well as protection against virulent M. tuberculosis challenge. In the present study, we examined in vivo tissue distribution of naked DNA-Hsp65 vaccine, the Hsp65 message, genome integration and methylation status of plasmid DNA. The DNA-Hsp65 was detectable in several tissue types, indicating that DNA-Hsp65 disseminates widely throughout the body. The biodistribution was dose-dependent. In contrast, RT-PCR detected the Hsp65 message for at least 15 days in muscle or liver tissue from immunized mice. We also analyzed the methylation status and integration of the injected plasmid DNA into the host cellular genome. The bacterial methylation pattern persisted for at least 6 months, indicating that the plasmid DNA-Hsp65 does not replicate in mammalian tissue, and Southern blot analysis showed that plasmid DNA was not integrated. These results have important implications for the use of DNA-Hsp65 vaccine in a clinical setting and open new perspectives for DNA vaccines and new considerations about the inoculation site and delivery system. 相似文献
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193.
Directional sensitivity of the abdominal giant fibers of the cricket to auditory stimulation has been investigated with special interest to the effect of the cerci position on the directional sensitivity of the giant neurons of the terminal abdominal ganglion. It has been shown that at least for some giant neurons the preferred directions of stimulation are practically independent of cerci position. (Fig. 2, 3). By other words these neurons have constant preferred directions in relation to the insect body, but not to the cerci. This property of giant neurons can be accounted for their changeable connections with many receptors having different directional selectivity. If innervation of the giant neuron is artificially restricted to one group of receptors with identical directional selectivity the described constancy of preferred directions in relation to the body disappears (Fig. 4). 相似文献
194.
Two independent types of lateral inhibition were distinguished in experiments on the frog eye in which the effects of pharmacological agents on the electroretinogram were studied: proximal or picrotoxin-sensitive, and distal or strychnine-sensitive. Distal lateral inhibition (at distances up to 1.5 mm) is the familiar type already well investigated and based on a spike mechanism of transmission of the inhibitory signal. The proximal (up to 400 µ) picrotoxin-sensitive inhibition has a different mechanism of transmission, not dependent on spikes. The localization of the two types of lateral inhibition in the synaptic layers of the frog retina is discussed.Institute for Problems in Information Transmission, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 13, No. 5, pp. 549–555, September–October, 1981. 相似文献
195.
196.
L Z Polishchuk 《T?Sitologii?a i genetika》1988,22(4):65-72
The data from home and foreign literature on chromosome changes in human tumours of different genesis and localization are analyzed. The role and significance of changes in the chromosome structure in malignant cells are discussed. 相似文献
197.
Copper is essential for a variety of important biological processes as a cofactor and regulator of many enzymes. Incorporation of copper into the secreted and plasma membrane-targeted cuproenzymes takes place in Golgi, a compartment central for normal copper homeostasis. The Golgi complex harbors copper-transporting ATPases, ATP7A and ATP7B that transfer copper from the cytosol into Golgi lumen for incorporation into copper-dependent enzymes. The Golgi complex also sends these ATPases to appropriate post-Golgi destinations to ensure correct Cu fluxes in the body and to avoid potentially toxic copper accumulation. Mutations in ATP7A or ATP7B or in the proteins that regulate their trafficking affect their exit from Golgi or subsequent retrieval to this organelle. This, in turn, disrupts the homeostatic Cu balance, resulting in copper deficiency (Menkes disease) or copper overload (Wilson disease). Research over the last decade has yielded significant insights into the enzymatic properties and cell biology of the copper ATPases. However, the mechanisms through which the Golgi regulates trafficking of ATP7A/7B and, therefore, maintains Cu homeostasis remain unclear. This review summarizes current data on the role of the Golgi in Cu metabolism and outlines questions and challenges that should be addressed to understand ATP7A and ATP7B trafficking mechanisms in health and disease. 相似文献
198.
Mitochondrial DNA variation and genetic structure in populations of Drosophila melanogaster 总被引:5,自引:0,他引:5
The understanding of the genetic structure of a species can be improved by
considering together data from different types of genetic markers. In the
past, a number of worldwide populations of Drosophila melanogaster have
been extensively studied for several such markers, including allozymes,
chromosomal inversions, and quantitative characters. Here we present
results from a study of restriction- fragment-length polymorphisms of
mitochondrial DNA (mtDNA) in 92 isofemale lines from many of the same
geographic populations of D. melanogaster. Eleven restriction enzymes were
used, of which four revealed restriction-site polymorphism. A total of 24
different haplotypes were observed, of which 18 were unique to single
populations. In many populations, the unique haplotypes have reached high
frequency without being observed in neighboring populations. A Wagner
parsimony tree reveals that mutationally close variants show geographical
clumping, suggesting local differentiation of mtDNA in populations. The
Old-World and the New-World populations are differentiated, with the
predominant Old-World haplotype being virtually absent from the New World.
These results contrast with those for the nuclear genes, in which many loci
show parallel clines in different continents, and suggest a common origin
of D. melanogaster populations in North America.
相似文献
199.
200.
Two of thirteen bacillar strains isolated from the inner tissues of cotton plants were found to produce type II restriction endonucleases. The investigation of the site specificity of these enzymes showed that they are AsuI and Eco31I isoschizomers. 相似文献