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11.
Serum-neutralizing antibody to VP4 and VP7 proteins in infants following vaccination with WC3 bovine rotavirus. 总被引:8,自引:2,他引:6 下载免费PDF全文
R L Ward D R Knowlton H B Greenberg G M Schiff D I Bernstein 《Journal of virology》1990,64(6):2687-2691
Serum specimens from infants 2 to 12 months old vaccinated with the WC3 bovine rotavirus were analyzed to determine the relative concentrations of neutralizing antibody to the VP4 and VP7 proteins of the vaccine virus. To do this, reassortant rotaviruses that contained the WC3 genome segment for only one of these two neutralization proteins were made. The segment for the other neutralization protein in these reassortants was from heterotypic rotaviruses that were serotypically distinct from WC3. Sera were examined from 31 infants who had no evidence of a previous rotavirus infection and the highest postvaccination WC3-neutralizing antibody titers (i.e., 160 to 600) of the 103 subjects administered the vaccine. A reassortant (3/17) that contained both neutralization proteins from the heterotypic rotaviruses, i.e., EDIM (EW strain of mouse rotavirus) VP7 and rhesus rotavirus VP4, was not neutralized by these sera (geometric mean titer [GMT], less than 20). A reassortant (E19) that contained EDIM VP7 and WC3 VP4 was also very poorly neutralized by these antisera (GMT = 20). In contrast, antibody titers to a reassortant (R20) that contained WC3 VP7 and rhesus rotavirus VP4 were higher than those against WC3 (GMTs of 458 and 313, respectively). Thus, VP7 appeared to be the dominant immunogen for production of neutralizing antibody after intestinal infection of previously uninfected infants vaccinated with WC3 bovine rotavirus. 相似文献
12.
13.
Stochastic versus deterministic variability in simple neuronal circuits: II. Hippocampal slice. 总被引:3,自引:3,他引:0
Long time series of Schaffer collateral to CA1 pyramidal cell presynaptic volleys (stratum radiatum) and population spikes (stratum pyramidale) were evoked (driven) in rat hippocampal slices. From the driven CA1 region in normal [K+] perfusate, both population spike amplitude and an input-output function consisting of population spike amplitude divided by the presynaptic volley amplitude were analyzed. Raising [K+] in the perfusion medium to 8.5 mM, slices were induced to spontaneously burst fire in CA3 and long time series of inter-burst intervals were recorded. Three tests for determinism were applied to these series: a discrete adaptation of a local flow approach, a local dispersion approach, and nonlinear prediction. Surrogate data were generated to serve as mathematical and statistical controls. All of the population spike (6/6) and input-output (6/6) time series from the normal [K+] driven circuitry were stochastic by all three methods. Although most of the time series (5/6) from the autonomously bursting high [K+] state failed to demonstrate evidence of determinism, one (1/6) of these time series did demonstrate significant determinism. This single instance of predictability could not be accounted for by the linear correlation in these data. 相似文献
14.
Effects of modeling and lineage on fishing behavior in the small-eared bushbaby (otolemur garnettii)
Sheree L. Watson Martha Schiff Jeannette P. Ward 《International journal of primatology》1994,15(4):507-519
Thirty-eight bushbabies(Otolemur garnettii)were subjects in an observational learning study. We exposed them to one of three modeling conditions: (1) fishing model—one
that actually performed fishing behavior; (2) nonfishing model—one that performed as a model in every way except performance
of fishing behavior; and (3) no model. We assessed them with regard to latency to approach the fishbowl, latency to make an
initial fishing attempt, duration of time spent in the vicinity of the fishbowls, and number of actual fishing attempts. Results
indicate that subjects that were exposed to either fishing or nonfishing models were faster to approach the fishbowls and
spent more time in the vicinity of the fishbowls than animals in the no-model condition Lineage, i.e., whether or not the
animals’ parents fished, rather than modeling condition, was the best predictor of the latency to initial fishing attempt
and the number of attempts made. 相似文献
15.
A major difference between the divergence patterns within the lines-1 families in mice and voles 总被引:3,自引:0,他引:3
Vanlerberghe F; Bonhomme F; Hutchison CA d; Edgell MH 《Molecular biology and evolution》1993,10(4):719-731
L1 retroposons are represented in mice by subfamilies of interspersed
sequences of varied abundance. Previous analyses have indicated that
subfamilies are generated by duplicative transposition of a small number of
members of the L1 family, the progeny of which then become a major
component of the murine L1 population, and are not due to any active
processes generating homology within preexisting groups of elements in a
particular species. In mice, more than a third of the L1 elements belong to
a clade that became active approximately 5 Mya and whose elements are >
or = 95% identical. We have collected sequence information from 13 L1
elements isolated from two species of voles (Rodentia: Microtinae: Microtus
and Arvicola) and have found that divergence within the vole L1 population
is quite different from that in mice, in that there is no abundant
subfamily of homologous elements. Individual L1 elements from voles are
very divergent from one another and belong to a clade that began a period
of elevated duplicative transposition approximately 13 Mya. Sequence
analyses of portions of these divergent L1 elements (approximately 250 bp
each) gave no evidence for concerted evolution having acted on the vole L1
elements since the split of the two vole lineages approximately 3.5 Mya;
that is, the observed interspecific divergence (6.7%-24.7%) is not larger
than the intraspecific divergence (7.9%-27.2%), and phylogenetic analyses
showed no clustering into Arvicola and Microtus clades.
相似文献
16.
Comparative sequence analysis of the reovirus S4 genes from 13 serotype 1 and serotype 3 field isolates. 总被引:5,自引:5,他引:0 下载免费PDF全文
The reovirus sigma 3 protein is a major outer capsid protein that may function to regulate translation within infected cells. To facilitate the understanding of sigma 3 structure and functions and the evolution of mammalian reoviruses, we sequenced cDNA copies of the S4 genes from 10 serotype 3 and 3 serotype 1 reovirus field isolates and compared these sequences with sequences of prototypic strains of the three reovirus serotypes. We found that the sigma 3 proteins are highly conserved: the two longest conserved regions contain motifs proposed to function in binding zinc and double-stranded RNA. We used the 16 viral isolates to investigate the hypothesis that structural interactions between sigma 3 and the cell attachment protein, sigma 1, constrain their evolution and to identify a determinant within sigma 3 that is in close proximity to the sigma 1 hemagglutination site. 相似文献
17.
In a previous study, nonlinear autoregressive (NLAR) models applied to ictal electroencephalogram (EEG) recordings in six
patients revealed nonlinear signal interactions that correlated with seizure type and clinical diagnosis. Here we interpret
these models from a theoretical viewpoint. Extended models with multiple nonlinear terms are employed to demonstrate the independence
of nonlinear dynamical interactions identified in the ‘NLAR fingerprint’ of patients with 3/s seizure discharges. Analysis
of the role of periodicity in the EEG signal reveals that the fingerprints reflect the dynamics not only of the periodic discharge
itself, but also of the fluctuations of each cycle about an average waveform. A stability analysis is used to make qualitative
inferences concerning the network properties of the ictal generators. Finally, the NLAR fingerprint is analyzed in the context
of Volterra-Weiner theory.
Received: 6 April 1994/Accepted in revised form: 18 November 1994 相似文献
18.
Henry R. Black Morton G. Glickman Martin Schiff Jr. Erik G. Pingoud 《The Yale journal of biology and medicine》1978,51(6):635-654
Renovascular hypertension can result from renal artery lesions involving the main renal artery, or its branches. It is generally felt that the elevation of blood pressure results from excessive systemic vasoconstriction secondary to enhanced renin secretion by one or part of one kidney. Renin secretion is enhanced because of constriction of the renal artery and resultant intrarenal ischemia. Clinically patients cannot be distinguished from those with essential hypertension and diagnosis must be made with arteriography although urography and isotope renography may suggest the diagnosis. Surgical cure can be predicted if differential renal vein renin ratios lateralize but a non-lateralizing study does not necessarily mean that surgery will fail. In properly selected patients, surgical results are excellent. 相似文献
19.
20.
Studies were initiated to determine the practicality of using various tissue cultures for the propagation of murine viruses isolated from laboratory animals. The cytopathogenic effects of 10 murine viruses known to cause disease in laboratory rodents were compared in monolayer cultures of L929, BHK-21, WI-38, BSC-1, and Vero cells. The susceptibility of primary hamster embryo, hamster kidney, mouse embryo, mouse kidney, and rat embryo cell cultures was also tested. Seven of the viruses produced effects in at least 1 of the cell substrates. The remaining 3 viruses, namely H-1, K, and mouse hepatitis, produced no effects in the cell cultures tested. 相似文献