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101.
Aren van Waarde Guido van den Thillart Fred Dobbe 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1982,147(1):53-59
Summary Changes in the concentrations of ammonia, glutamate, alanine, aspartate, -ketoglutarate, oxaloacetate and succinate were measured in freeze-clamped lateralred muscle, dorsal white muscle and liver, and in rapidly cooled blood of goldfish after 12 h of anoxia. Alanine accumulation, succinate accumulation and aspartate depletion are observed in all tissues examined; in the liver the concentrations of glutamate increase and those of ammonia decrease. The mass-action ratio of the glutamate-pyruvate transaminase-catalyzed reaction stays within one order of magnitude from thermodynamic equilibrium in the direction of alanine formation. The mass-action ratio of the glutamate-oxaloacetate transaminase reaction is far from equilibrium when measured oxaloacetate concentrations are used. When levels of free oxaloacetate are calculated from LDH and MDH equilibrium constants, the mass-action ratio of glutamate-oxaloacetate transamination is close to equilibrium in the direction of aspartate formation. Since neither alanine nor glutamate decreases, and since ammonia gradients suggest a continuous ammonia production in all tissues examined, anaerobic proteolysis is assumed. A possible coupling between amino acid catabolism and ethanol production is discussed.Abbreviations
ALA
alanine
-
ASP
aspartate
-
EDTA
ethylene diamine tetraacetate
-
FP
ox
oxidated flavoprotein
-
FP
red
reduced flavoprotein
-
FUM
fumarate
-
GLU
glutamate
-
GOT
glutamate oxaloacetate transaminase
-
GPT
glutamate pyruvate transaminase
-
IMP
inosine monophosphate
- KG
-ketoglutarate
-
LDH
lactate dehydrogenase
-
MAL
malate
-
MAR
mass action ratio
-
MDH
malate dehydrogenase
-
OAA
oxaloacetate
-
PYR
pyruvate
-
sAMP
adenylosuccinate
-
SDH
succinate dehydrogenase
-
SUCC
succinate 相似文献
102.
Summary All the five enzymes of urea synthesis and the formation of urea in vitro can already be demonstrated in human liver as early as the 9th week of fetal development. At this stage the activity of carbamoyl phosphate synthetase is the highest, whereas that of ornithine carbamoyltransferase is the lowest as compared to those in the adult. The kinetic parameters of the urea cycle enzymes are the same in fetal liver as in adult liver, except that the Km values of ornithine carbamoyltransferase for L-ornithine are 3.5 mM and 0.42 mM in the fetus and in adult liver, respectively.Urea formation in vivo seems to begin in the second half of fetal life, and a gradual increase can be detected in the activity of the enzymes of urea synthesis. The activity of ortnithine decarboxylase, the glutamine-dependent carbamoyl phosphate synthetase and aspartate carbamoyltransferase, however, changes in the opposite direction.The concentration of carbamoyl phosphate and aspartate remains constant, but that of ornithine gradually decreases during ontogenesis. The ornithine, carbamoyl phosphate and aspartate pools are probably utilized in the polyamine, pyrimidine and urea syntheses at varying rates. 相似文献
103.
Tyrosinase and L-DOPA decarboxylase activities have been investigated during Bufo bufo development since catecholamines and melanin are formed from common substrates in homologous cells. Catecholamines first appear at stage 13 (neural plate), but tyrosinase, at a very low level, and L-DOPA decarboxylase are present throughout all of prior development. Hence, L-DOPA decarboxylase activity is not likely to be correlated with the control of catecholamine synthesis, although at stage 17 it is mainly localized in the nonneural part of the embryo. The distribution of young melanosomes and L-DOPA decarboxylase suggest a separation between melanogenesis and catecholamine synthesis. 相似文献
104.
Guido Chelazzi Stefano Focardi 《Journal of experimental marine biology and ecology》1982,65(3):263-273
Zonal oscillations of Monodonta turbinata (Born) were monitored with an actographic device which precluded clustering behaviour. Unfed snails maintained their cyclic pattern of behaviour for up to 8 days under a light-dark cycle which simulated the natural one. Under constant conditions of light or dark, however, the snails ceased migration and occupied a zonal position typical of day and night, respectively. Experiments in diffuse light and with light from below the floor of the experimental tank showed that the downward migration of M. turbinata in the daytime depends on positive geotaxis combined with negative phototaxis whilst the upward migration at night depends on a negative geotaxis. This mechanism is similar to that described in other littoral molluscs. There was no evidence of an endogenous control of rhythmic zonal activity. 相似文献
105.
Herman L. De Pooter Patrick J. Dirinck Guido A. Willaert Niceas M. Schamp 《Phytochemistry》1981,20(9):2135-2138
The headspace of whole Golden Delicious apples treated with propionic acid vapour, was analysed by means of GC, after enrichment on Tenax GC, and its c 相似文献
106.
107.
108.
Wafa H. Cabrera Olga M. Ibanez Silvio L. Oliveira Osvaldo A. Sant'Anna Maria Siqueira Denise Mouton Guido Biozzi 《Immunogenetics》1982,16(6):583-592
The effect of the selective breeding of mice for high or low antibody production to complex immunogens is largely nonspecific, since it modifies the responsiveness of high (H) and low (L) lines to many antigens unrelated to the selection antigen. However, the nonspecific effect of the polygenic control operating in these lines is not a general feature. For example, the group of genes in selection IV, carried out for responsiveness to somatic antigen of Salmonella, does not modify the responses to sheep erythrocytes (SE). Despite equivalent responses in H and L mice of selection IV, a large variability was found in individual responses of F2 interline hybrids, which demonstrates the presence of alleles with high or low effect on responses to SE. A selective breeding (Selection IV-A) was therefore initiated from this F2 population for responsiveness to SE. A progressive interline divergence occurred during the first seven generations of selection; the interline separation was due to polygenic regulation (about four independent loci from a preliminary estimate).Equivalent responses to the s antigen of Salmonella are observed in the two lines. This constitutes additional evidence for distinct polygenic regulation of responses to SE and to somatic antigen. Moreover, the pattern of responses to several unrelated antigens (nonspecific effect) also differs between Selections IV and IV-A.Abbreviations H
high responder lines
- L
low responder lines
- s
somatic antigen of Salmonella
- f
flagellar antigen of Salmonella
- R
response to selection
- S
selection differential
- F0
foundation population
- h2
heritability (realized)
- RGG
rabbit gamma globulin
- CE
chicken erythrocyte
- HE
human erythrocyte
- PE
pigeon erythrocyte
- SE
sheep erythrocyte 相似文献
109.
110.
Denise Mouton Anne -Marie Heumann Yolande Bouthillier Jean Claude Mevel Guido Biozzi 《Immunogenetics》1979,8(1):475-486
The antibody response to a threshold dose (10) of SE was studied in the High responder line (H) and the Low responder line (L) of mice obtained by bidirectional selective breeding for the character quantitative agglutinin response to an optimal dose of SE, and in interline hybrids: F1, F1 and both backcrosses. Whereas the interline difference in agglutinin responses at the optimal dose is due to the additive effect of about ten independently segregating loci, one of which isH-2 linked, the responsiveness to the threshold dose is determined by the effect of two loci. The direction of the dominance effect also varies with the antigen dose: high responsiveness is partially dominant at the optimal dose while at the threshold dose nonresponder character is partially dominant. The role of theH-2 linked locus was investigated. It has been demonstrated that on an identical background (equivalent to that of F1 hybrids) this locus is responsible for 12% of the interline difference at the optimal antigen dose, and for 61% at the threshold antigen dose. For the two antigen doses, the quantitative effect of theH-2 locus is in agreement with the estimate of the number of loci obtained by variance analysis. The intervention of a second gene, non-H-2 linked, in the regulation of responsiveness to 106 SE is demonstrated by appropriate assortative matings. The interaction between the two genes is discussed. 相似文献